Clinical Focus


  • Cancer > Breast Cancer
  • Cancer > Radiation Oncology
  • Breast Cancer
  • Breast Cancer - Radiation Oncology
  • Breast Cancer - Partial Breast Irradiation
  • Radiation Oncology
  • Radiation Therapy

Academic Appointments


Professional Education


  • Internship: Santa Clara Valley Medical Center (2000) CA
  • Residency: Stanford University Radiation Oncology Residency (2004) CA
  • Board Certification: American Board of Radiology, Radiation Oncology (2005)
  • Medical Education: Stanford University School of Medicine (1999) CA

Clinical Trials


  • Assessment of Patient Experience During Treatment for Cancer Recruiting

    Assessing the mindset of cancer patients will help us better understand which patients are having difficulty dealing with the diagnosis and treatment that may not otherwise be fully appreciated by their physicians. By identifying such patients, we may then be able to design and implement strategies that can help improve their coping skills both during the treatment as well as after the completion of treatment. In addition to addressing physical concerns and symptoms, this approach will help address the overall emotional impact of a cancer diagnosis as more patients are living as cancer survivors.

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  • Accelerated Partial Breast Irradiation Following Lumpectomy for Breast Cancer Not Recruiting

    To determine whether an accelerated course of radiotherapy delivered to the lumpectomy cavity plus margin using IORT as a single dose, intracavitary brachytherapy with the MammoSite device over 5 days, partial breast 3-D CRT in 5 days, or stereotactic APBI over 4 days is a feasible and safe alternative to a six and a half week course of whole breast radiotherapy. The study will measure both short and long-term complications of radiation treatment, short and long-term breast cosmesis, local rates of in-breast cancer recurrence, regional recurrences, distant metastases, and overall survival.

    Stanford is currently not accepting patients for this trial. For more information, please contact Sally Bobo, (650) 736 - 1472.

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  • Breast Density and the Role of Preoperative Mammography, Ultrasound, Elastography and MRI Not Recruiting

    To determine the sensitivity, specificity, and accuracy of preoperative ultrasound, elastography, mammography and breast MRI in women with dense breast tissue diagnosed with breast cancer; to test whether elastography or MRI can improve upon routine mammogram and conventional ultrasound in women with dense breast tissue.

    Stanford is currently not accepting patients for this trial. For more information, please contact Leslie Roche, (650) 724 - 5913.

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  • CyberKnife Radiosurgical Treatment of Inoperable Early Stage Non-Small Cell Lung Cancer Not Recruiting

    The purpose of this study is to assess the short and long-term outcomes after CyberKnife stereotactic radiosurgery for early stage non-small cell lung cancer (NSCLC) in patients who are medically inoperable.

    Stanford is currently not accepting patients for this trial. For more information, please contact Lisa Zhou, (650) 736 - 4112.

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  • Cyberknife® Partial Breast Irradiation (PBI) for Early Stage Breast Cancer Not Recruiting

    By using stereotactic body radiation therapy (SBRT) delivered with the Cyberknife system®, the current protocol attempts to mimic or improve the excellent local control rates seen in treatment of early stage breast cancer while attempting to increase convenience, limit invasiveness, decrease toxicity, and improve cosmesis compared to other methods of radiation treatment.

    Stanford is currently not accepting patients for this trial. For more information, please contact Katherine Fero, (650) 736 - 0921.

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  • Radiation Therapy With or Without Trastuzumab in Treating Women With Ductal Carcinoma In Situ Who Have Undergone Lumpectomy Not Recruiting

    This randomized phase III trial studies radiation therapy to see how well it works with or without trastuzumab in treating women with ductal carcinoma in situ who have undergone lumpectomy. Monoclonal antibodies, such as trastuzumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Radiation therapy uses high-energy x-rays to kill tumor cells. It is not yet known whether radiation therapy is more effective with or without trastuzumab in treating ductal carcinoma in situ.

    Stanford is currently not accepting patients for this trial. For more information, please contact Amy Isaacson, 650-723-0501.

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2020-21 Courses


Stanford Advisees


  • Postdoctoral Faculty Sponsor
    Katy Balazy

All Publications


  • Telemedicine in Radiation Oncology: Is It Here to Stay? Impacts on Patient Care and Resident Education. International journal of radiation oncology, biology, physics Gutkin, P. M., Prionas, N. D., Minneci, M. O., Allen, E. 3., Balazy, K. E., Rahimy, E., Chang, D. T., Horst, K. C. 2020; 108 (2): 416–20

    Abstract

    PURPOSE: Telemedicine was rapidly and ubiquitously adopted during the COVID-19 pandemic. However, there are growing discussions as to its role postpandemic.METHODS AND MATERIALS: We surveyed patients, radiation oncology (RO) attendings, and RO residents to assess their experience with telemedicine. Surveys addressed quality of patient care and utility of telemedicine for teaching and learning core competencies. Satisfaction was rated on a 6-point Likert-type scale. The quality of teaching and learning was graded on a 5-point Likert-type scale, with overall scores calculated by the average rating of each core competency required by the Accreditation Council for Graduate Medical Education (range, 1-5).RESULTS: Responses were collected from 56 patients, 12 RO attendings, and 13 RO residents. Patient feedback was collected at 17 new-patient, 22 on-treatment, and 17 follow-up video visits. Overall, 88% of patients were satisfied with virtual visits. A lower proportion of on-treatment patients rated their virtual visit as "very satisfactory" (68.2% vs 76.5% for new patients and 82.4% for follow-ups). Only 5.9% of the new patients and none of the follow-up patients were dissatisfied, and 27% of on-treatment patients were dissatisfied. The large majority of patients (88%) indicated that they would continue to use virtual visits as long as a physical examination was not needed. Overall scores for medical training were 4.1 out of 5 (range, 2.8-5.0) by RO residents and 3.2 (range, 2.0-4.0) by RO attendings. All residents and 92% of attendings indicated they would use telemedicine again; however, most indicated that telemedicine is best for follow-up visits.CONCLUSIONS: Telemedicine is a convenient means of delivering care to patients, with some limitations demonstrated for on-treatment patients. The majority of both patients and providers are interested in using telemedicine again, and it will likely continue to supplement patient care.

    View details for DOI 10.1016/j.ijrobp.2020.06.047

    View details for PubMedID 32890524

  • Lymphopenia and clinical outcomes in patients with residual nodal disease after neoadjuvant chemotherapy for breast cancer. Cancer causes & control : CCC Gutkin, P. M., Kozak, M. M., von Eyben, R., Horst, K. C. 2020

    Abstract

    BACKGROUND: Patients with residual nodal disease after neoadjuvant chemotherapy for breast cancer have a poor prognosis. We wanted to evaluate whether lymphopenia after treatment for breast cancer impacted clinical outcomes.MATERIALS AND METHODS: We assessed 99 patients with node-positive disease after neoadjuvant chemotherapy. Absolute lymphocyte count was recorded 1year after radiation. Dates of local, regional, and distant failure were recorded. Time to event outcomes were evaluated using Kaplan-Meier analysis. Multivariable analysis determined factors predictive for overall survival.RESULTS: Median follow-up was 44months (range 3-150). Median age was 48years (range 23-79). Twenty-six patients (26%) had lymphopenia 1 year after RT. Patients with lymphopenia had a greater incidence of regional (p=0.03) and distant failure (p=0.009) compared to those with normal lymphocyte counts and had a 6.05 greater risk of death (p=0.0002).CONCLUSIONS: In patients with residual nodal disease after neoadjuvant chemotherapy, lymphopenia after breast cancer treatment was associated with overall survival. The relationship between lymphopenia and breast cancer outcomes warrants further investigation.

    View details for DOI 10.1007/s10552-020-01337-6

    View details for PubMedID 32888164

  • Development of a Classification Tree to Predict Implant-Based Reconstruction Failure with or without Postmastectomy Radiation Therapy for Breast Cancer. Annals of surgical oncology Chen, J. J., von Eyben, R., Gutkin, P. M., Hawley, E., Dirbas, F. M., Lee, G. K., Horst, K. C. 2020

    Abstract

    PURPOSE: The aim of this study was to determine the complications, incidence, and predictors of implant-based reconstruction failure (RF) among patients treated with mastectomy for breast cancer.METHODS: We retrospectively reviewed 108 patients who underwent mastectomy, tissue expander, and implant-based breast reconstruction with or without radiation therapy (RT) at our institution (2000-2014). Descriptive statistics determined complication incidences, with major complications defined as any complications requiring surgical intervention or inpatient management. Chi square and Fisher's exact tests determined differences in RF incidences, defined as implant loss. Logistic regression analyses identified predictors of RF.RESULTS: Median follow-up was 42.5months. Sixty patients (55.6%) experienced major complications. Overall, 27 patients (25%) experienced RF. Incidences of RF were significantly increased in patients who had any major complication (43.3% vs. 2.1%; p<0.0001), especially infection (61.3% vs. 10.4%; p<0.0001), delayed wound healing (83.3% vs. 21.7%; p=0.004), and implant exposure (80.0% vs. 19.4%; p=0.0002). Receiving RT, but not timing of RT, significantly predicted RF [odds ratio (OR) 4.00, 95% confidence interval (CI) 1.11-14.47; p=0.03]. On multivariable analysis, infection (OR 7.69, 95% CI 2.12-27.89; p=0.002) and delayed wound healing (OR 17.86, 95% CI 1.59-200.48; p=0.02) independently predicted for RF. Our newly developed classification tree, which includes stepwise assessment of major infection, delayed wound healing, implant exposure, age ≥50years, and total number of lymph nodes removed ≥10, accurately predicted 74% of RF events and 75% of non-RF events.CONCLUSIONS: Infection or delayed wound healing requiring surgical intervention or hospitalization and receipt of RT, but not radiation timing, were significant predictors of RF. Our classification tree demonstrated >70% accuracy for stepwise prediction of RF.

    View details for DOI 10.1245/s10434-020-09068-3

    View details for PubMedID 32875465

  • ASO Author Reflections: Sequential Decision Tree Analysis Reveals Pivotal Branch Points in Predicting Implant-Based Reconstruction Failure Outcomes. Annals of surgical oncology Chen, J. J., Horst, K. C. 2020

    View details for DOI 10.1245/s10434-020-09093-2

    View details for PubMedID 32875466

  • Impact of mastectomy for breast cancer on spinal curvature: Considerations when treating patients with scoliosis. The breast journal Gutkin, P. M., Kapp, D. S., von Eyben, R., Dirbas, F. M., Horst, K. C. 2020

    Abstract

    OBJECTIVE: Mastectomy has been shown to influence body posture in women; however, there are limited data outlining changes in spine curvature after mastectomy in patients with scoliosis. We sought to quantify changes in spine curvature after mastectomy for breast cancer.METHODS: We conducted a retrospective review of 62 patients with scoliosis who underwent mastectomy for breast cancer at a single institution between 1995 and 2018. Preoperative and postoperative radiographs were used to measure Cobb angles to assess lateral spinal curvature. Changes in Cobb angle were compared using paired two-tailed t-tests. The relationship between mass of breast removed and changes in Cobb angle was modeled using a linear regression.RESULTS: The median follow-up after mastectomy was 7.9years (range 0.9-21.5). Median age was 62years (range 30-85). Of 62 patients, 10 (16%) expressed that their back pain became worse after mastectomy. Nineteen patients had evaluable radiographs before and after mastectomy. In these patients, the average change in Cobb angle was 4.7° (range -0.2-12.2). Cobb angle significantly increased after mastectomy (P<.0001). Although not statistically significant, average Cobb angle was greater for patients who underwent unilateral compared to bilateral mastectomy (P=.09). Mass of breast removed significantly correlated with the difference in Cobb angle for patients who underwent unilateral mastectomy (P=.0006), but not for bilateral mastectomy (P=.55).CONCLUSIONS: In this understudied patient population, mastectomy significantly increased the change in spine curvature. Further care should be taken to assess patient-reported pain and quality of life in patients with spine morbidity who undergo mastectomy for breast cancer.

    View details for DOI 10.1111/tbj.14018

    View details for PubMedID 32841452

  • Continuing Medical Student Education During the Coronavirus Disease 2019 (COVID-19) Pandemic: Development of a Virtual Radiation Oncology Clerkship. Advances in radiation oncology Pollom, E. L., Sandhu, N., Frank, J., Miller, J. A., Obeid, J., Kastelowitz, N., Panjwani, N., Soltys, S. G., Bagshaw, H. P., Donaldson, S. S., Horst, K., Beadle, B. M., Chang, D. T., Gibbs, I. 2020; 5 (4): 732–36

    Abstract

    Purpose: Our institution cancelled all in-person clerkships owing to the coronavirus disease 2019 pandemic. In response, we designed a virtual radiation oncology medical student clerkship.Methods and Materials: We convened an advisory panel to design a virtual clerkship curriculum. We implemented clerkship activities using a cloud-based learning management system, video web conferencing systems, and a telemedicine portal. Students completed assessments pre- and postclerkship to provide data to improve future versions of the clerkship.Results: The virtual clerkship spans 2 weeks and is graded pass or fail. Students attend interactive didactic sessions during the first week and participate in virtual clinic and give talks to the department during the second week. Didactic sessions include lectures, case-based discussions, treatment planning seminars, and material adapted from the Radiation Oncology Education Collaborative Study Group curriculum. Students also attend virtual departmental quality assurance rounds, cancer center seminars, and multidisciplinary tumor boards. The enrollment cap was met during the first virtual clerkship period (April 27 through May 8, 2020), with a total of 12 students enrolling.Conclusions: Our virtual clerkship can increase student exposure and engagement in radiation oncology. Data on clerkship outcomes are forthcoming.

    View details for DOI 10.1016/j.adro.2020.05.006

    View details for PubMedID 32775783

  • Patterns of Failure in Women Who Have Residual Nodal Disease After Neoadjuvant Chemotherapy for Breast Cancer According to Extent of Lymph Node Surgery. Clinical breast cancer Kozak, M. M., Horst, K. C., Gutkin, P. M., Jacobson, C. E., Walck, E., von Eyben, R., Dirbas, F. M. 2020

    Abstract

    BACKGROUND: Optimal surgical management of limited axillary nodal disease following neoadjuvant chemotherapy (NAC) for breast cancer is evolving. Concerns exist with respect to leaving residual disease in the axilla when omitting axillary lymph node dissection (ALND) in this setting. We sought to determine whether extent of nodal surgery altered patterns of failure and patient outcomes.PATIENTS AND METHODS: We identified 70 patients with breast cancer who were confirmed cN0 after NAC yet had residual nodal disease (ypN1) on sentinel lymph node biopsy (SLNB). Twenty-eight patients underwent SLNB alone and 42 underwent SLNB+completion (c)ALND in a non-randomized fashion. Most (n= 65) patients underwent adjuvant regional nodal irradiation (RNI). Detailed patterns of failure data were obtained for each patient.RESULTS: The median follow-up was 43.5 months. There were 30 (43%) recurrences. Of these, 5 were isolated locoregional failures, and 24 were distant failures. There were no significant differences in local (P= .13), regional (P= .62), or distant (P= .47) failure between patients who underwent SLNB alone versus SLNB+cALND. Seventeen (24%) patients died. Overall survival was similar in both groups with median overall survival not reached for those who underwent SLNB and 109 months for those who underwent SLNB+cALND (P= .45).CONCLUSIONS: There were no differences in patterns of recurrence among patients with 1 to 3 involved lymph nodes after NAC who underwent SLNB alone versus SLNB+cALND in the setting of RNI. We await the results of ongoing, prospective clinical trials to confirm the relative merits of RNI in lieu of cALND in these patients.

    View details for DOI 10.1016/j.clbc.2020.04.008

    View details for PubMedID 32522481

  • A randomized phase II study comparing surgical excision versus NeOadjuvant Radiotherapy followed by delayed surgical excision of Ductal carcinoma In Situ (NORDIS) Wapnir, I., DeMartini, W., Allison, K., Stone, K., Dirbas, F., Marquez, C., Ikeda, D., Pal, S., Tsai, J., Yang, R., West, R., McMillan, A., Telli, M., Horst, K. AMER ASSOC CANCER RESEARCH. 2020
  • Health mindset is associated with anxiety and depression in patients undergoing treatment for breast cancer. The breast journal Gutkin, P. M., Fero, K. E., Jacobson, C. E., Chen, J. J., Liang, R. V., Kolar, C., von Eyben, R., Horst, K. C. 2020

    View details for DOI 10.1111/tbj.13765

    View details for PubMedID 31999018

  • Virtual Radiation Oncology Clerkship During the COVID-19 Pandemic and Beyond. International journal of radiation oncology, biology, physics Sandhu, N., Frank, J., von Eyben, R., Miller, J., Obeid, J., Kastelowitz, N., Panjwani, N., Soltys, S., Bagshaw, H. P., Donaldson, S. S., Horst, K., Beadle, B. M., Chang, D. T., Gibbs, I. C., Pollom, E. 2020; 108 (2): 444–51

    Abstract

    PURPOSE: We evaluated the impact of a virtual radiation oncology clerkship.METHODS AND MATERIALS: We developed a 2-week virtual radiation oncology clerkship that launched on April 27, 2020. Clerkship components included a virtual clinic with radiation oncology faculty and residents, didactic lectures, student talks, and supplemental sessions such as tumor boards and chart rounds. Medical students completed pre- and post-clerkship self-assessments. Faculty and resident participants also completed surveys on their experience with virtual lectures and clinics. Pre- and post-clerkship results were compared using a 2-sided paired t test. An analysis of variance model was used to analyze the clerkship components.RESULTS: Twenty-six medical students, including 4 visiting students, enrolled over 2 clerkship periods (4 weeks). All students completed the pre- and post-clerkship self-assessments and agreed that the clerkship improved their understanding of radiation oncology. Compared with 3 (11.5%) students who agreed that they understood the daily responsibilities of a radiation oncologist before the clerkship, 22 (84.6%) students agreed and 3 (11.5%) strongly agreed that they understood the daily responsibilities of a radiation oncologist after the clerkship (P < .0001). Although 15 students (57.7%) reported an increased interest in radiation oncology because of the clerkship, the mean level of interest in radiation oncology as a career remained the same, with pre- and post-clerkship scores of 3.0 (±0.9) and 3.0 (±1.1) on a 5-point scale, respectively (P = .7). Students found virtual clinic and didactic lectures to be the most valuable components of the clerkship. Most respondents agreed (30.8%) or strongly agreed (65.4%) to recommend the clerkship to their classmates.CONCLUSIONS: Our virtual clerkship was effective in increasing medical student interest in and knowledge about radiation oncology. These data will help optimize a new paradigm of virtual radiation oncology education for medical students during COVID-19 and beyond.

    View details for DOI 10.1016/j.ijrobp.2020.06.050

    View details for PubMedID 32890529

  • Angiosarcoma of the Breast: Management and Outcomes. American journal of clinical oncology Gutkin, P. M., Ganjoo, K. N., Lohman, M., von Eyben, R., Charville, G. W., Nazerali, R. S., Dirbas, F. M., Horst, K. C. 2020

    Abstract

    Angiosarcoma of the breast is rare and has a poor prognosis. We reviewed our institution's experience with this disease to characterize presentation, identify management patterns, and report outcomes.Fifty-eight patients with nonmetastatic angiosarcoma were identified from 1998 to 2019 and retrospectively reviewed. Overall survival (OS) and recurrence-free survival (RFS) were calculated using the Kaplan-Meier analysis and log-rank test.The median follow-up was 43.4 months (range: 1.8 to 203.3 mo). Twenty-four patients had primary angiosarcoma (PAS) and 34 patients had secondary angiosarcoma (SAS). Patients with PAS were significantly younger than those with SAS (P<0.0001). Mastectomy was the main surgical treatment in our cohort (n=47) and 3 underwent a lumpectomy. The multifocal disease was found in 5/23 patients with PAS and 11/35 patients with SAS. Twenty-eight patients received chemotherapy. Radiation was administered to 13 patients with PAS and 3 patients with SAS. Five-year OS was 73.7% for PAS and 63.5% for SAS. Local recurrence occurred in a greater proportion of patients with margins <5 mm than those with margins ≥5 mm. Chemotherapy did not impact RFS and was not associated with OS in PAS (P=0.35). Those with SAS treated with chemotherapy had significantly greater OS than those who did not receive chemotherapy (P=0.043). Radiation did not significantly influence RFS or OS.Five-year OS was higher than anticipated. Margins >5 mm appear important for local control. Patients with SAS, but not PAS, may achieve improved survival with chemotherapy. National trials using prespecified agents may be needed to identify an optimal chemotherapy regimen for women with SAS.

    View details for DOI 10.1097/COC.0000000000000753

    View details for PubMedID 32889893

  • Erythema of the skin after breast radiotherapy: It is not always recurrence. International wound journal Gutkin, P. M., Fernandez-Pol, S., Horst, K. C. 2020

    Abstract

    Recurrence of breast cancer is a predominant fear for patients who were treated for breast cancer. Acute and late dermatologic effects of radiotherapy are not uncommon and could have similar characteristics to breast cancer recurrence. Thus, it is important to highlight key differences between the clinical and histologic presentations of radiation effects and recurrence. Herein, we present two patients who presented with late dermatologic effects of radiotherapy months to years after treatment, neither of whom had workup consistent with cancer recurrence. We provide clinical and microscopic descriptions of each case and provide a review to differentiate various dermatologic conditions. This report aims to outline potential late dermatologic effects of radiation treatment and emphasise that changes in the breast do not always signal breast cancer recurrence.

    View details for DOI 10.1111/iwj.13350

    View details for PubMedID 32227450

  • Importance of a Culture Committee for Boosting Morale and Maintaining a Healthy Work Environment in Radiation Oncology. Advances in radiation oncology Gutkin, P. M., Minneci, M. O., Valenton, J., Kovalchuk, N., Chang, D. T., Horst, K. C. 2020

    Abstract

    During the unprecedented workplace disruption from the corona virus disease 2019 (COVID-19) pandemic, health care workers have been particularly vulnerable to increased work-related stress and anxiety. This may have a negative effect on job performance and personal well-being. Personal safety, job security, and childcare needs are essential concerns that must be addressed by health care organizations to ensure stability of its workforce. In addition, workplace morale is also damaged by the many daily changes brought about by social distancing. Thus, opportunities exist for departments to address the loss of social bonding and cohesiveness needed for successful team building. In this report, we describe the efforts of our departmental workplace culture committee during this pandemic.

    View details for DOI 10.1016/j.adro.2020.07.002

    View details for PubMedID 32838068

    View details for PubMedCentralID PMC7368646

  • Postmastectomy and Regional Nodal Radiation for Breast Cancer. Journal of clinical oncology : official journal of the American Society of Clinical Oncology Torres, M. A., Horst, K. C., Freedman, G. M. 2020: JCO1902908

    View details for DOI 10.1200/JCO.19.02908

    View details for PubMedID 32442076

  • Use of Preoperative Radiation Therapy in Early-stage and Locally Advanced Breast Cancer CUREUS Koenig, J. L., Kozak, M. M., Sabolch, A., Horst, K., Tsai, J., Wapnir, I. L., Pollom, E. 2019; 11 (9)
  • Association between primary language, a lack of mammographic screening, and later stage breast cancer presentation CANCER Balazy, K. E., Benitez, C. M., Gutkin, P. M., Jacobson, C. E., von Eyben, R., Horst, K. C. 2019; 125 (12): 2057–65

    View details for DOI 10.1002/cncr.32027

    View details for Web of Science ID 000470925600016

  • Adjuvant treatment and survival in older women with triple negative breast cancer: A Surveillance, Epidemiology, and End Results analysis. The breast journal Kozak, M. M., Xiang, M., Pollom, E. L., Horst, K. C. 2019

    Abstract

    Patients with triple negative breast cancer were identified using the Surveillance, Epidemiology, and End Results database. Competing risks analysis was used to assess the cumulative incidence of breast cancer-specific mortality (BCSM). Multivariable Fine-Gray regression was used to identify predictors of BCSM. Women age 70+ (n=4221) were less likely to receive chemotherapy and radiation treatment (P<0.0001) and had higher BCSM compared to younger women (P<0.0001). There were no differences in BCSM in patients who received adjuvant treatment (P=0.10). Stage II patients derived the greatest relative and absolute benefit from adjuvant treatment. Age was not a significant predictor of BCSM.

    View details for DOI 10.1111/tbj.13251

    View details for PubMedID 30925635

  • Association between primary language, a lack of mammographic screening, and later stage breast cancer presentation. Cancer Balazy, K. E., Benitez, C. M., Gutkin, P. M., Jacobson, C. E., von Eyben, R., Horst, K. C. 2019

    Abstract

    BACKGROUND: Health determinants are known to influence the stage of breast cancer presentation, but it is unclear to what extent language affects stage. This study investigates whether non-English-speaking (NES) patients present at a later stage than their English-speaking (ES) counterparts and whether language is associated with mammographic screening.METHODS: This study was a retrospective, single-institution cohort analysis of women undergoing breast radiotherapy from 2012 to 2017 (n=1057). Patients were categorized as ES (n=904) or NES (n=153). Ordinal logistic regression analysis identified variables associated with later stage presentation, including language, race/ethnicity, and age. A subcohort analysis investigated the influence of mammographic screening on stage for NES patients.RESULTS: NES patients had greater odds of later stage disease than ES patients (odds ratio, 1.47; 95% confidence, 1.001-2.150). This association persisted across all races/ethnicities. An additional analysis examined age categories associated with mammographic screening. For women eligible for screening (ie, those 40-50years old or older than 50years), there was a significant association between language and stage. NES patients older than 50years were twice as likely to present at an advanced stage in comparison with ES patients (16.19% vs 8.11%; P=.0082). An additional subset analysis accounted for mammograms. NES patients who did not undergo screening had a higher probability of stage III disease (40.3% of NES patients vs 12.7% of ES patients). There was no difference in stage between NES and ES patients who did undergo screening.CONCLUSIONS: Language is independently associated with later stage breast cancer for NES patients, regardless of race/ethnicity. NES patients may have difficulty in accessing the health care system. Future interventions should seek to reduce language barriers for mammographic screening and diagnosis.

    View details for PubMedID 30768784

  • Corrigendum to 'Clinical perineural invasion of cutaneous head and neck cancer: Impact of radiotherapy, imaging, and nerve growth factor receptors on symptom control and prognosis'. [Oral Oncol. 85 (2018) 60-67]. Oral oncology Chen, J. J., Harris, J. P., Kong, C. S., Sunwoo, J. B., Divi, V., Horst, K. C., Aasi, S. Z., Hollmig, S. T., Hara, W. Y. 2019

    View details for DOI 10.1016/j.oraloncology.2019.05.024

    View details for PubMedID 31174982

  • Systemic Inflammation after Radiation Predicts Locoregional Recurrence, Progression, and Mortality in Stage II-III Triple-Negative Breast Cancer. International journal of radiation oncology, biology, physics Sherry, A. D., von Eyben, R., Newman, N. B., Gutkin, P., Mayer, I., Horst, K., Chakravarthy, A. B., Rafat, M. 2019

    Abstract

    Patients with triple-negative breast cancer experience high rates of recurrence following radiation, which may be facilitated by the recruitment of circulating tumor cells to pro-inflammatory microenvironments in the absence of lymphocytes. We hypothesized that patients with lymphopenia and elevated inflammatory hematologic markers after radiotherapy would have an increased risk of locoregional failure.With approval, we retrospectively studied a cohort of women treated with adjuvant radiotherapy for stage II-III triple-negative breast cancer. We analyzed the relationship between post-radiotherapy neutrophil:lymphocyte ratio (NLR) and locoregional recurrence by Cox regression.130 patients met inclusion criteria, and median follow up time was 7.6 years. Patients with an NLR ≥ 3 had a higher rate of locoregional failure (p=0.04) and lower overall survival (p=0.04). After adjusting for stage (HR = 5.5, p < 0.0001) and neoadjuvant chemotherapy (HR = 2.5, p = 0.0162), NLR was highly predictive of locoregional failure, (HR = 1.4, p = 0.0009). NLR was also highly predictive of overall survival (HR = 1.3, p = 0.0007) after adjustment for stage and neoadjuvant chemotherapy.Innate peripheral inflammation following radiotherapy for triple-negative breast cancer in an immunocompromised setting may be a novel prognostic biomarker for locoregional recurrence, progression, and survival. This finding supports preclinical studies of post-radiotherapy inflammation-mediated tumor progression. Further studies are needed to confirm this finding and develop treatment strategies.

    View details for DOI 10.1016/j.ijrobp.2019.11.398

    View details for PubMedID 31809877

  • Use of Preoperative Radiation Therapy in Early-stage and Locally Advanced Breast Cancer. Cureus Koenig, J. L., Kozak, M. M., Sabolch, A., Horst, K., Tsai, J., Wapnir, I. L., Pollom, E. 2019; 11 (9): e5748

    Abstract

    Purpose There is growing interest in delivering radiation preoperatively (preopRT) rather than postoperatively (postopRT) for breast cancer. Using the National Cancer Database, we evaluated the use and outcomes of preopRT in breast cancer. Methods We identified adult females diagnosed with non-metastatic breast cancer treated with definitive surgery and radiation between 2004 and 2014. Logistic regression models evaluated factors associated with use of preopRT in early-stage (clinical T1-3/N0-1) and locally advanced (clinical T4/N2-3) disease. Rates of breast-conserving surgery, breast reconstruction, positive surgical margins, and 30-day surgical readmissions were compared between patients receiving preopRT and postopRT. Results Of 373,595 patients who met our inclusion criteria, 1,245 (0.3%) patients received preopRT. Patients receiving preopRT were more likely to be of lower socioeconomic status and have tumors with higher T stage. Younger age and N1 (vs N0) disease predicted for use of preopRT in early-stage disease, while older age and N0 disease predicted for use of preopRT in the locally advanced setting. PreopRT patients were less likely to undergo breast-conserving surgery and more likely to have positive surgical margins. Rates of unplanned readmissions within 30 days of surgery were similar among patients treated with preopRT and postopRT. Conclusions PreopRT is a new treatment strategy for patients with breast cancer with different clinical and sociodemographic drivers of its use in the early-stage and locally advanced settings. We await the results of clinical trials studying the efficacy of this approach.

    View details for DOI 10.7759/cureus.5748

    View details for PubMedID 31723509

    View details for PubMedCentralID PMC6825433

  • Integrating Radiosensitivity and Immune Gene Signatures for Predicting Benefit of Radiotherapy in Breast Cancer CLINICAL CANCER RESEARCH Cui, Y., Li, B., Pollom, E. L., Horst, K. C., Li, R. 2018; 24 (19): 4754–62
  • Clinical perineural invasion of cutaneous head and neck cancer: Impact of radiotherapy, imaging, and nerve growth factor receptors on symptom control and prognosis. Oral oncology Chen, J. J., Harris, J. P., Kong, C. S., Sunwoo, J. B., Divi, V., Horst, K. C., Aasi, S. Z., Hollmig, S. T., Hara, W. Y. 2018; 85: 60–67

    Abstract

    OBJECTIVES: Clinical perineural invasion (CPNI) of cutaneous head and neck cancer is associated with poor prognosis and presents a therapeutic dilemma. The purpose of this study was to determine the relationship between CPNI and nerve growth factor receptors (NGFR), and the impact of radiotherapy (RT), imaging, and NGFR on symptom control and disease-related outcomes.MATERIALS AND METHODS: We retrospectively reviewed patients with CPNI of cutaneous head and neck cancer who were treated with RT between 2010 and 2015 at our institution. Exact chi-square and Wilcoxon rank-sum tests compared patients with positive versus negative staining for TrkA and/or CD271. Gray's test determined differences in cumulative incidences of 1- and 2-year locoregional recurrence (LRR) and cancer-specific mortality (CSM).RESULTS: Twenty-three patients had a median overall follow-up of 31.4 months from initial clinical symptoms and 19.7 months from pathological confirmation of PNI. The most prevalent symptoms were numbness (70%) and pain (57%). Sixteen patients (70%) experienced symptom improvement or control, especially decreased pain (85%), within a median of 2.6 months from starting RT. The 1- and 2-year rates of overall LRR were 37% and 71%, while those of overall CSM were 11% and 25%, respectively. Patients who stained positively for TrkA and/or CD271 had significantly worse LRR compared to patients who stained negatively for both markers (p = 0.046).CONCLUSION: Positive TrkA and/or CD271 staining predicts worse outcomes. Patients may benefit from aggressive RT for local control and symptom improvement. Future research is needed to identify the potential for anti-nerve growth factor therapies in CPNI.

    View details for PubMedID 30220321

  • Outcomes Following Neoadjuvant Chemotherapy for Breast Cancer in Women Aged 40 Years and Younger: Impact of Pathologic Nodal Response. Journal of the National Comprehensive Cancer Network : JNCCN Kozak, M. M., Jacobson, C. E., von Eyben, R., Pollom, E. L., Telli, M., Horst, K. C. 2018; 16 (7): 845–50

    Abstract

    Purpose: We sought to evaluate whether pathologic nodal response was predictive of outcomes in women aged ≤40 years with breast cancer treated with neoadjuvant chemotherapy (NAC). Methods: A total of 220 patients treated with NAC between 1991 and 2015 were retrospectively reviewed. Pathologic complete response (pCR) was defined as no evidence of residual invasive tumor in the breast and lymph nodes (LNs) (ypT0/Tis ypN0); partial response if there was no tumor in the LNs but residual tumor in the breast (ypT+ ypN0) or residual tumor in the LNs (ypT0/Tis ypN+); and limited response if there was residual tumor in both the breast and the LNs (ypT+ ypN+). Kaplan-Meier and Cox proportional hazards analyses were performed to identify factors predictive for overall survival (OS). Results: A total of 155 patients were included. Following NAC, 39 patients (25.2%) achieved pCR, 57 (36.8%) achieved a partial response (either ypT+ ypN0 or ypT0/Tis ypN+), and 59 (38.1%) had a limited response. A total of 22 patients (14.2%) experienced local failure, 20 (12.9%) experienced regional failure, and 59 (38.1%) experienced distant failure. Median OS for patients who achieved pCR was not reached, and was significantly worse for patients who had residual disease in the breast and/or LNs (P<.001). No difference in OS was seen among patients who had residual disease in the breast alone versus those who remained LN-positive (97 vs 83 months, respectively; P=.25). Subset analysis did not reveal differences in OS based on year of treatment or cN1 disease at the time of initial diagnosis. Conclusions: Women aged ≤40 years who achieved pCR had excellent outcomes; however, those who achieved a pathologic response in the LNs but had residual disease in the breast continued to have outcomes similar to those who remained LN-positive.

    View details for DOI 10.6004/jnccn.2018.7022

    View details for PubMedID 30006427

  • Integrating Radiosensitivity and Immune Gene Signatures for Predicting Benefit of Radiotherapy in Breast Cancer. Clinical cancer research : an official journal of the American Association for Cancer Research Cui, Y., Li, B., Pollom, E. L., Horst, K., Li, R. 2018

    Abstract

    PURPOSE: Breast cancer is a heterogeneous disease and not all patients respond equally to adjuvant radiotherapy. Predictive biomarkers are needed to select patients who will benefit from the treatment and spare others the toxicity and burden of radiation.EXPERIMENTAL DESIGN: We first trained and tested an intrinsic radiosensitivity gene signature to predict local recurrence after radiotherapy in three cohorts of 948 patients. Next, we developed an antigen processing and presentation-based immune signature by maximizing the treatment interaction effect in 129 patients. To test their predictive value, we matched patients treated with or without radiotherapy in an independent validation cohort for clinicopathologic factors including age, ER status, HER2 status, stage, hormone-therapy, chemotherapy, and surgery. Disease specific survival (DSS) was the primary endpoint.RESULTS: Our validation cohort consisted of 1,439 patients. After matching and stratification by the radiosensitivity signature, patients who received radiotherapy had better DSS than patients who did not in the radiation-sensitive group (hazard ratio [HR]=0.68, P=0.059, n=322), while a reverse trend was observed in the radiation-resistant group (HR=1.53, P=0.059, n=202). Similarly, patients treated with radiotherapy had significantly better DSS in the immuneeffective group (HR=0.46, P=0.0076, n=180), with no difference in DSS in the immunedefective group (HR=1.27, P=0.16, n=348). Both signatures were predictive of radiotherapy benefit (Pinteraction=0.007 and 0.005). Integration of radiosensitivity and immune signatures further stratified patients into three groups with differential outcomes for those treated with or without radiotherapy (Pinteraction=0.003).CONCLUSIONS: The proposed signatures have the potential to select patients who are most likely to benefit from radiotherapy.

    View details for PubMedID 29921729

  • Radiation therapy for the whole breast: Executive summary of an American Society for Radiation Oncology (ASTRO) evidence-based guideline PRACTICAL RADIATION ONCOLOGY Smith, B. D., Bellon, J. R., Blitzblau, R., Freedman, G., Haffty, B., Hahn, C., Halberg, F., Hoffman, K., Horst, K., Moran, J., Patton, C., Perlmutter, J., Warren, L., Whelan, T., Wright, J. L., Jagsi, R. 2018; 8 (3): 145–52

    Abstract

    The purpose of this guideline is to offer recommendations on fractionation for whole breast irradiation (WBI) with or without a tumor bed boost and guidance on treatment planning and delivery.The American Society for Radiation Oncology (ASTRO) convened a task force to address 5 key questions focused on dose-fractionation for WBI, indications and dose-fractionation for tumor bed boost, and treatment planning techniques for WBI and tumor bed boost. Guideline recommendations were based on a systematic literature review and created using a predefined consensus-building methodology supported by ASTRO-approved tools for grading evidence quality and recommendation strength.For women with invasive breast cancer receiving WBI with or without inclusion of the low axilla, the preferred dose-fractionation scheme is hypofractionated WBI to a dose of 4000 cGy in 15 fractions or 4250 cGy in 16 fractions. The guideline discusses factors that might or should affect fractionation decisions. Use of boost should be based on shared decision-making that considers patient, tumor, and treatment factors, and the task force delineates specific subgroups in which it recommends or suggests use or omission of boost, along with dose recommendations. When planning, the volume of breast tissue receiving >105% of the prescription dose should be minimized and the tumor bed contoured with a goal of coverage with at least 95% of the prescription dose. Dose to the heart, contralateral breast, lung, and other normal tissues should be minimized.WBI represents a significant portion of radiation oncology practice, and these recommendations are intended to offer the groundwork for defining evidence-based practice for this common and important modality. This guideline also seeks to promote appropriately individualized, shared decision-making regarding WBI between physicians and patients.

    View details for PubMedID 29545124

  • Detection of local recurrence in premenopausal patients treated with neoadjuvant chemotherapy and mastectomy with or without breast reconstruction Jacobson, C. E., Kozak, M., Walck, E., Hawley, E., Horst, K. AMER ASSOC CANCER RESEARCH. 2018
  • National trends in mastectomy for operable breast cancers treated with neoadjuvant chemotherapy Pollom, E., Qian, Y., Dirbas, F., Horst, K., Tsai, C. AMER ASSOC CANCER RESEARCH. 2018
  • Macrophages Promote Circulating Tumor Cell-Mediated Local Recurrence Following Radiation Therapy in Immunosuppressed Patients. Cancer research Rafat, M., Aguilera, T. A., Vilalta, M., Bronsart, L. L., Soto, L. A., von Eyben, R., Golla, M. A., Ahrari, Y., Melemenidis, S., Afghahi, A., Jenkins, M. J., Kurian, A. W., Horst, K., Giaccia, A. J., Graves, E. E. 2018

    Abstract

    Although radiation therapy (RT) decreases the incidence of locoregional recurrence in breast cancer, patients with triple-negative breast cancer (TNBC) have increased risk of local recurrence following breast-conserving therapy (BCT). The relationship between RT and local recurrence is unknown. Here we tested the hypothesis that recurrence in some instances is due to the attraction of circulating tumor cells to irradiated tissues. To evaluate the effect of absolute lymphocyte count on local recurrence after RT in TNBC patients, we analyzed radiation effects on tumor and immune cell recruitment to tissues in an orthotopic breast cancer model. Recurrent patients exhibited a prolonged low absolute lymphocyte count when compared to non-recurrent patients following RT. Recruitment of tumor cells to irradiated normal tissues was enhanced in the absence of CD8+ T cells. Macrophages (CD11b+F480+) preceded tumor cell infiltration and were recruited to tissues following RT. Tumor cell recruitment was mitigated by inhibiting macrophage infiltration using maraviroc, an FDA-approved CCR5 receptor antagonist. Our work poses the intriguing possibility that excessive macrophage infiltration in the absence of lymphocytes promotes local recurrence after RT. This combination thus defines a high-risk group of TNBC patients.

    View details for PubMedID 29880480

  • Characteristics and clinical outcomes of pleomorphic lobular carcinoma in situ of the breast BREAST JOURNAL Fasola, C. E., Chen, J., Jensen, K. C., Allison, K. H., Horst, K. C. 2018; 24 (1): 66–69

    Abstract

    Pleomorphic lobular carcinoma in situ (PLCIS) of the breast is a rare variant of lobular carcinoma in situ (LCIS). We reviewed 78 cases of PLCIS diagnosed at our institution from 1998 to 2012. Among all cases, 47 (60%) were associated with invasive carcinoma and/or ductal carcinoma in situ (DCIS) after final surgical excision. Of the 20 cases with PLCIS alone on core needle biopsy (CNB), 6 (30%) were upgraded to invasive carcinoma or DCIS after final surgical excision. Our findings support a recommendation for complete surgical excision of PLCIS when diagnosed on CNB.

    View details for PubMedID 28929550

  • Patterns of Distant Failure by Intrinsic Breast Cancer Subtype in Premenopausal Women Treated With Neoadjuvant Chemotherapy. Clinical breast cancer Kozak, M. M., Jacobson, C. E., von Eyben, R., Walck, E., Pollom, E. L., Telli, M., Horst, K. C. 2018

    Abstract

    To identify patterns of distant failure (DF) in premenopausal women receiving neoadjuvant chemotherapy (NAC) for breast cancer.Premenopausal patients treated with NAC between 2005 and 2015 at a single institution were retrospectively reviewed. Timing and location of local, regional, and distant metastases were described. Predictors for DF and overall survival (OS) were analyzed.Of 225 patients, there were 24 (10.7%) local, 30 (13.3%) regional, and 63 (28.0%) distant recurrences. Cumulative incidence of DF was higher in patients younger than age 40 (P = .01), in those with residual tumor size > 2 cm (P < .0001), in those with positive lymph nodes after NAC (P = .0003), and in those without pathologic complete response (P < .0001). Cumulative incidence of brain metastases was most common in patients with human epidermal growth factor receptor 2 (HER2)-positive disease (P = .05). Time from development of metastatic disease to death varied by breast cancer subtype (P = .019), as did 5-year OS (P = .024). Women with HER2-positive and triple-negative disease had the highest incidence of brain metastases and the shortest time from development of metastases to death. On multivariable analysis, luminal B subtype (P = .025), pathologic complete response (P = .0014), young age (P = .0008), lack of hormone therapy (P < .0001), lymphovascular space involvement (P < .0001), and pathologic size of the primary tumor (P < .0001) were all significant predictors for DF.Patterns of DF after NAC in premenopausal women vary by breast cancer subtype, with DF more common than locoregional failure. Young age remains an independent poor prognostic factor, and OS differs by breast cancer subtype.

    View details for PubMedID 29843987

  • Impact of Insurance Coverage on Outcomes in Primary Breast Sarcoma. Sarcoma Koenig, J. L., Tsai, C. J., Sborov, K., Horst, K. C., Pollom, E. L. 2018; 2018: 4626174

    Abstract

    Private insurance is associated with better outcomes in multiple common cancers. We hypothesized that insurance status would significantly impact outcomes in primary breast sarcoma (PBS) due to the additional challenges of diagnosing and coordinating specialized care for a rare cancer. Using the National Cancer Database, we identified adult females diagnosed with PBS between 2004 and 2013. The influence of insurance status on overall survival (OS) was evaluated using the Kaplan-Meier estimator with log-rank tests and Cox proportional hazard models. Among a cohort of 607 patients, 67 (11.0%) had Medicaid, 217 (35.7%) had Medicare, and 323 (53.2%) had private insurance. Compared to privately insured patients, Medicaid patients were more likely to present with larger tumors and have their first surgical procedure further after diagnosis. Treatment was similar between patients with comparable disease stage. In multivariate analysis, Medicaid (hazard ratio (HR), 2.47; 95% confidence interval (CI), 1.62-3.77; p < 0.001) and Medicare (HR, 1.68; 95% CI, 1.10-2.57; p=0.017) were independently associated with worse OS. Medicaid insurance coverage negatively impacted survival compared to private insurance more in breast sarcoma than in breast carcinoma (interaction p < 0.001). In conclusion, patients with Medicaid insurance present with later stage disease and have worse overall survival than privately insured patients with PBS. Worse outcomes for Medicaid patients are exacerbated in this rare cancer.

    View details for PubMedID 29736143

    View details for PubMedCentralID PMC5875066

  • Rising rates of bilateral mastectomy with reconstruction following neoadjuvant chemotherapy. International journal of cancer Pollom, E. L., Qian, Y., Chin, A. L., Dirbas, F. M., Asch, S. M., Kurian, A. W., Horst, K. C., Tsai, C. J. 2018

    Abstract

    Neoadjuvant chemotherapy is used to allow more limited breast surgery without compromising local control. We sought to evaluate nationwide surgical trends in patients with operable breast cancer treated with neoadjuvant chemotherapy and factors associated with surgical type. We used the National Cancer Database to identify 235,339 women with unilateral T1-3N0-3M0 breast cancer diagnosed between 2010 and 2014, and treated with surgery and chemotherapy. Of these, 59,568 patients (25.3%) were treated with neoadjuvant chemotherapy. Rates of pathologic complete response to neoadjuvant chemotherapy increased from 33.3% at the start of the study period in 2010 to 46.3% at the end of the period in 2014 (p=0.02). Rates of breast-conserving surgery changed little, from 37.0% to 40.8% (p=0.22). While rates of unilateral mastectomy decreased from 43.3% to 34.7% (p=0.02) and rates of bilateral mastectomy without immediate reconstruction remained similar (11.7% to 11.5%, p=0.82), rates of bilateral mastectomy with immediate reconstruction rose from 8.0% to 13.1% (p=0.02). Patients who were younger, with private/managed care insurance, and diagnosed in more recent years were more likely to achieve pathologic complete response; however, these same characteristics were associated with receipt of bilateral mastectomy (versus breast-conserving surgery). Additionally, non-Hispanic white race and higher area education attainment were both associated with bilateral mastectomy. These findings did not differ by age or molecular subtype. Further study of non-clinical factors that influence selection of more extensive surgery despite excellent response to neoadjuvant chemotherapy is warranted. This article is protected by copyright. All rights reserved.

    View details for PubMedID 29992582

  • Higher Absolute Lymphocyte Counts Predict Lower Mortality from Early-Stage Triple-Negative Breast Cancer. Clinical cancer research : an official journal of the American Association for Cancer Research Afghahi, A., Purington, N., Han, S. S., Desai, M., Pierson, E., Mathur, M. B., Seto, T., Thompson, C. A., Rigdon, J., Telli, M. L., Badve, S. S., Curtis, C., West, R. B., Horst, K., Gomez, S. L., Ford, J. M., Sledge, G. W., Kurian, A. W. 2018

    Abstract

    Tumor-infiltrating lymphocytes (TILs) in pre-treatment biopsies are associated with improved survival in triple-negative breast cancer (TNBC). We investigated whether higher peripheral lymphocyte counts are associated with lower breast cancer-specific mortality (BCM) and overall mortality (OM) in TNBC.Data on treatments and diagnostic tests from electronic medical records of two healthcare systems were linked with demographic, clinical, pathologic, and mortality data from the California Cancer Registry. Multivariable regression models adjusted for age, race/ethnicity, socioeconomic status, cancer stage, grade, neoadjuvant/adjuvant chemotherapy use, radiotherapy use, and germline BRCA1/2 mutations were used to evaluate associations between absolute lymphocyte count (ALC), BCM and OM. For a subgroup with TILs data available, we explored the relationship between TILs and peripheral lymphocyte counts.1,463 Stage I-III TNBC patients were diagnosed from 2000-2014; 1113 (76%) received neoadjuvant/adjuvant chemotherapy within one year of diagnosis. Of 759 patients with available ALC data, 481 (63.4%) were ever lymphopenic (minimum ALC <1.0 K/μL). On multivariable analysis, higher minimum ALC, but not absolute neutrophil count, predicted lower OM (hazard ratio [HR]: 0.23, 95% confidence interval [CI]: 0.16-0.35) and BCM (HR: 0.19, CI: 0.11-0.34). Five-year probability of BCM was 15% for patients who were ever lymphopenic versus 4% for those who were not. An exploratory analysis (N=70) showed a significant association between TILs and higher peripheral lymphocyte counts during neoadjuvant chemotherapy.Higher peripheral lymphocyte counts predicted lower mortality from early-stage, potentially curable TNBC, suggesting that immune function may enhance the effectiveness of early TNBC treatment.

    View details for PubMedID 29581131

  • Clinical Utility of the 12-Gene DCIS Score Assay: Impact on Radiotherapy Recommendations for Patients with Ductal Carcinoma In Situ ANNALS OF SURGICAL ONCOLOGY Manders, J. B., Kuerer, H. M., Smith, B. D., McCluskey, C., Farrar, W. B., Frazier, T. G., Li, L., Leonard, C. E., Carter, D. L., Chawla, S., Medeiros, L. E., Guenther, J. M., Castellini, L. E., Buchholz, D. J., Mamounas, E. P., Wapnir, I. L., Horst, K. C., Chagpar, A., Evans, S. B., Riker, A. I., Vali, F. S., Solin, L. J., Jablon, L., Recht, A., Sharma, R., Lu, R., Sing, A. P., Hwang, E. S., White, J. 2017; 24 (3): 660-668

    Abstract

    The aim of this study was to determine the impact of the results of the 12-gene DCIS Score assay on (i) radiotherapy recommendations for patients with pure ductal carcinoma in situ (DCIS) following breast-conserving surgery (BCS), and (ii) patient decisional conflict and state anxiety.Thirteen sites across the US enrolled patients (March 2014-August 2015) with pure DCIS undergoing BCS. Prospectively collected data included clinicopathologic factors, physician estimates of local recurrence risk, DCIS Score results, and pre-/post-assay radiotherapy recommendations for each patient made by a surgeon and a radiation oncologist. Patients completed pre-/post-assay decisional conflict scale and state-trait anxiety inventory instruments.The analysis cohort included 127 patients: median age 60 years, 80 % postmenopausal, median size 8 mm (39 % ≤5 mm), 70 % grade 1/2, 88 % estrogen receptor-positive, 75 % progesterone receptor-positive, 54 % with comedo necrosis, and 18 % multifocal. Sixty-six percent of patients had low DCIS Score results, 20 % had intermediate DCIS Score results, and 14 % had high DCIS Score results; the median result was 21 (range 0-84). Pre-assay, surgeons and radiation oncologists recommended radiotherapy for 70.9 and 72.4 % of patients, respectively. Post-assay, 26.4 % of overall recommendations changed, including 30.7 and 22.0 % of recommendations by surgeons and radiation oncologists, respectively. Among patients with confirmed completed questionnaires (n = 32), decision conflict (p = 0.004) and state anxiety (p = 0.042) decreased significantly from pre- to post-assay.Individualized risk estimates from the DCIS Score assay provide valuable information to physicians and patients. Post-assay, in response to DCIS Score results, surgeons changed treatment recommendations more often than radiation oncologists. Further investigation is needed to better understand how such treatment changes may affect clinical outcomes.

    View details for DOI 10.1245/s10434-016-5583-7

    View details for Web of Science ID 000394178600011

    View details for PubMedCentralID PMC5306072

  • Will oncotype DX DCIS testing guide therapy? A single-institution correlation of oncotype DX DCIS results with histopathologic findings and clinical management decisions. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc Lin, C. Y., Mooney, K., Choy, W., Yang, S. R., Barry-Holson, K., Horst, K., Wapnir, I., Allison, K. 2017

    Abstract

    Given the increased detection rates of ductal carcinoma in situ (DCIS) and the limited overall survival benefit from adjuvant breast irradiation after breast-conserving surgery, there is interest in identifying subsets of patients who have low rates of ipsilateral breast tumor recurrence such that they might safely forgo radiation. The Oncotype DCIS score is a reverse transcription-PCR (RT-PCR)-based assay that was validated to predict which DCIS cases are most likely to recur. Clinically, these results may be used to assist in selecting which patients with DCIS might safely forgo radiation therapy after breast-conserving surgery; however, little is currently published on how this test is being used in practice. Our study examines traditional histopathologic features used in predicting DCIS risk with Oncotype DCIS results and how these results affect clinical decision-making at our academic institution. Histopathologic features and management decisions for 37 cases with Oncotype DCIS results over the past 4 years were collected. Necrosis, high nuclear grade, biopsy site change, estrogen receptor and progesterone receptor positivity <90% on immunohistochemistry, and Van Nuys Prognostic Index score of 8 or greater were significant predictors of an intermediate-high recurrence score on multivariate regression analysis (P<0.02). Low Oncotype DCIS scores and low nuclear grade were associated with lower rate of radiation therapy (P<0.008). There were seven cases (19%) with Oncotype DCIS results that we considered unexpected in relation to the histopathologic findings (ie, high nuclear grade with comedonecrosis and a low Oncotype score, or hormone receptor discrepancies). Overall, pathologic features correlate with Oncotype DCIS scores but unexpected results do occur, making individual recommendations sometimes challenging.Modern Pathology advance online publication, 15 December 2017; doi:10.1038/modpathol.2017.172.

    View details for PubMedID 29243740

  • Clinical Utility of the 12-Gene DCIS Score Assay: Impact on Radiotherapy Recommendations for Patients with Ductal Carcinoma In Situ. Annals of surgical oncology Manders, J. B., Kuerer, H. M., Smith, B. D., McCluskey, C., Farrar, W. B., Frazier, T. G., Li, L., Leonard, C. E., Carter, D. L., Chawla, S., Medeiros, L. E., Guenther, J. M., Castellini, L. E., Buchholz, D. J., Mamounas, E. P., Wapnir, I. L., Horst, K. C., Chagpar, A., Evans, S. B., Riker, A. I., Vali, F. S., Solin, L. J., Jablon, L., Recht, A., Sharma, R., Lu, R., Sing, A. P., Hwang, E. S., White, J. 2016: -?

    Abstract

    The aim of this study was to determine the impact of the results of the 12-gene DCIS Score assay on (i) radiotherapy recommendations for patients with pure ductal carcinoma in situ (DCIS) following breast-conserving surgery (BCS), and (ii) patient decisional conflict and state anxiety.Thirteen sites across the US enrolled patients (March 2014-August 2015) with pure DCIS undergoing BCS. Prospectively collected data included clinicopathologic factors, physician estimates of local recurrence risk, DCIS Score results, and pre-/post-assay radiotherapy recommendations for each patient made by a surgeon and a radiation oncologist. Patients completed pre-/post-assay decisional conflict scale and state-trait anxiety inventory instruments.The analysis cohort included 127 patients: median age 60 years, 80 % postmenopausal, median size 8 mm (39 % ≤5 mm), 70 % grade 1/2, 88 % estrogen receptor-positive, 75 % progesterone receptor-positive, 54 % with comedo necrosis, and 18 % multifocal. Sixty-six percent of patients had low DCIS Score results, 20 % had intermediate DCIS Score results, and 14 % had high DCIS Score results; the median result was 21 (range 0-84). Pre-assay, surgeons and radiation oncologists recommended radiotherapy for 70.9 and 72.4 % of patients, respectively. Post-assay, 26.4 % of overall recommendations changed, including 30.7 and 22.0 % of recommendations by surgeons and radiation oncologists, respectively. Among patients with confirmed completed questionnaires (n = 32), decision conflict (p = 0.004) and state anxiety (p = 0.042) decreased significantly from pre- to post-assay.Individualized risk estimates from the DCIS Score assay provide valuable information to physicians and patients. Post-assay, in response to DCIS Score results, surgeons changed treatment recommendations more often than radiation oncologists. Further investigation is needed to better understand how such treatment changes may affect clinical outcomes.

    View details for PubMedID 27704370

  • Reply to R. Colomer et al. Journal of clinical oncology Durkee, B. Y., Qian, Y., Goldhaber-Fiebert, J. D., Horst, K. C. 2016; 34 (26): 3227-3228

    View details for DOI 10.1200/JCO.2016.68.4084

    View details for PubMedID 27432936

  • Five-year results of a prospective clinical trial investigating accelerated partial breast irradiation using 3D conformal radiotherapy after lumpectomy for early stage breast cancer BREAST Horst, K. C., Fasola, C., Ikeda, D., Daniel, B., Ognibene, G., Goffinet, D. R., Dirbas, F. M. 2016; 28: 178-183

    Abstract

    Accelerated partial breast irradiation (APBI) is emerging as an alternative to whole-breast irradiation. This study presents the results of a prospective trial evaluating 3-dimensional conformal radiotherapy (3D-CRT) to deliver APBI for early-stage breast cancer.Patients with unifocal stage 0-II breast cancer measuring ≤2.5 cm without lymph node involvement were eligible. After lumpectomy, 3D-CRT APBI was delivered to the lumpectomy cavity + margin (34-38.5 Gy in 10 fractions over 5 days).141 patients with 143 breast cancers (2 bilateral) were treated with 3D-CRT APBI. Median age was 60. Median tumor size was 1.1 cm. At a median follow up of 60 months (range, 5-113), the 5-year and 8-year cumulative incidence rate of a true recurrence is 0.9%. The 5-year and 8-year cumulative incidence rates of an elsewhere failure are 2.4% and 4.4%, respectively. The 5-year and 8-year overall survival is 100% and 94%, respectively. Among the 62 patients with follow up >5 years, 95% had excellent/good cosmetic results.Our experience with 3D-CRT APBI demonstrates excellent cosmesis and local control. Longer follow up will be necessary to evaluate long-term efficacy and toxicity of 3D-CRT APBI. CLINICALTRIALS.NCT00185744.

    View details for DOI 10.1016/j.breast.2016.06.001

    View details for Web of Science ID 000379683300027

    View details for PubMedID 27322859

  • CT-Guided Wire Localization for Involved Axillary Lymph Nodes After Neo-adjuvant Chemotherapy in Patients With Initially Node-Positive Breast Cancer BREAST JOURNAL Long Trinh, L., Miyake, K. K., Dirbas, F. M., Kothary, N., Horst, K. C., Lipson, J. A., Carpenter, C., Thompson, A. C., Ikeda, D. M. 2016; 22 (4): 390-396

    Abstract

    Resection of biopsy-proven involved axillary lymph nodes (iALNs) is important to reduce the false-negative rates of sentinel lymph node (SLN) biopsy after neo-adjuvant chemotherapy (NAC) in patients with initially node-positive breast cancer. Preoperative wire localization for iALNs marked with clips placed during biopsy is a technique that may help the removal of iALNs after NAC. However, ultrasound (US)-guided localization is often difficult because the clips cannot always be reliably visible on US. Computed tomography (CT)-guided wire localization can be used; however, to date there have been no reports on CT-guided wire localization for iALNs. The aim of this study was to describe a series of patients who received CT-guided wire localization for iALN removal after NAC and to evaluate the feasibility of this technique. We retrospectively analyzed five women with initially node-positive breast cancer (age, 41-52 years) who were scheduled for SLN biopsy after NAC and received preoperative CT-guided wire localization for iALNs. CT visualized all the clips that were not identified on post-NAC US. The wire tip was deployed beyond or at the target, with the shortest distance between the wire and the index clip ranging from 0 to 2.5 mm. The total procedure time was 21-38 minutes with good patient tolerance and no complications. In four of five cases, CT wire localization aided in identification and resection of iALNs that were not identified with lymphatic mapping. Residual nodal disease was confirmed in two cases: both had residual disease in wire-localized lymph nodes in addition to SLNs. Although further studies with more cases are required, our results suggest that CT-guided wire localization for iALNs is a feasible technique that facilitates identification and removal of the iALNs as part of SLN biopsy after NAC in situations where US localization is unsuccessful.

    View details for DOI 10.1111/tbj.12597

    View details for PubMedID 27061012

  • Breast Imaging in Women Previously Irradiated for Hodgkin Lymphoma. American journal of clinical oncology Horst, K. C., Fero, K. E., Hancock, S. L., Advani, R. H., Ikeda, D. M., Daniel, B., Rosenberg, S. A., Donaldson, S. S., Hoppe, R. T. 2016; 39 (2): 114-119

    Abstract

    Women treated with mantle irradiation for Hodgkin lymphoma (HL) are at an increased risk of developing breast cancer (BC). Current guidelines recommend screening breast magnetic resonance imaging (MRI) as an adjunct to mammography (M) in these patients. There are limited data, however, as to the impact of breast MRI on cancer detection rates. The aim of the current study is to evaluate the use of breast MRI in survivors of HL treated and followed at a single institution.We retrospectively reviewed 980 female patients treated with mantle irradiation for HL between 1961 and 2008. Records were reviewed to determine age at radiotherapy treatment, radiotherapy dose, breast imaging (including M and breast MRI), biopsy results if applicable, and incidence of BC.A total of 118 patients had breast imaging performed at our institution. Median age at HL diagnosis was 28 years (range, 10 to 69 y). Median radiotherapy dose was 36 Gy (range, 20 to 45 Gy). Seventy-nine patients (67%) underwent M screening only, 1 (1%) breast MRI only, and 38 (32%) both M and breast MRI. Of these 38, 19 (50%) underwent 54 screening MRI studies (range per patient=1 to 8), 13 (34%) underwent preoperative MRI for workup of BC, and 6 (16%) initiated screening MRI of the contralateral breast only after diagnosed with BC. Fifty-nine biopsies were performed: 47 were prompted by suspicious M findings only, 10 by palpable findings on physical examination (PE), and 2 by suspicious breast MRI findings. Of the 47 biopsies prompted by M, 24 revealed malignant disease, whereas 23 proved to be benign. All 10 biopsies performed by palpation were malignant. Both biopsies prompted by MRI findings were benign. With M, there were 34 true-positive findings in 32 patients, 23 false-positive findings, and 1 false-negative finding. With screening MRI, there were 2 false-positive findings, 1 false-negative finding, and no true-positive findings.The role of screening breast MRI in women previously irradiated for HL is evolving. Further education of patients and physicians is important to increase awareness of more sensitive BC screening modalities in this high-risk population. Future studies are necessary to determine the appropriate integration of screening breast MRI into the ongoing follow-up of these women.

    View details for DOI 10.1097/COC.0000000000000025

    View details for PubMedID 24390271

  • Cost-Effectiveness of Pertuzumab in Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer. Journal of clinical oncology Durkee, B. Y., Qian, Y., Pollom, E. L., King, M. T., Dudley, S. A., Shaffer, J. L., Chang, D. T., Gibbs, I. C., Goldhaber-Fiebert, J. D., Horst, K. C. 2016; 34 (9): 902-909

    Abstract

    The Clinical Evaluation of Pertuzumab and Trastuzumab (CLEOPATRA) study showed a 15.7-month survival benefit with the addition of pertuzumab to docetaxel and trastuzumab (THP) as first-line treatment for patients with human epidermal growth factor receptor 2 (HER2) -overexpressing metastatic breast cancer. We performed a cost-effectiveness analysis to assess the value of adding pertuzumab.We developed a decision-analytic Markov model to evaluate the cost effectiveness of docetaxel plus trastuzumab (TH) with or without pertuzumab in US patients with metastatic breast cancer. The model followed patients weekly over their remaining lifetimes. Health states included stable disease, progressing disease, hospice, and death. Transition probabilities were based on the CLEOPATRA study. Costs reflected the 2014 Medicare rates. Health state utilities were the same as those used in other recent cost-effectiveness studies of trastuzumab and pertuzumab. Outcomes included health benefits expressed as discounted quality-adjusted life-years (QALYs), costs in US dollars, and cost effectiveness expressed as an incremental cost-effectiveness ratio. One- and multiway deterministic and probabilistic sensitivity analyses explored the effects of specific assumptions.Modeled median survival was 39.4 months for TH and 56.9 months for THP. The addition of pertuzumab resulted in an additional 1.82 life-years gained, or 0.64 QALYs, at a cost of $713,219 per QALY gained. Deterministic sensitivity analysis showed that THP is unlikely to be cost effective even under the most favorable assumptions, and probabilistic sensitivity analysis predicted 0% chance of cost effectiveness at a willingness to pay of $100,000 per QALY gained.THP in patients with metastatic HER2-positive breast cancer is unlikely to be cost effective in the United States.

    View details for DOI 10.1200/JCO.2015.62.9105

    View details for PubMedID 26351332

  • Impact of a Sit-Stand Workstation on Chronic Low Back Pain: Results of a Randomized Trial. Journal of occupational and environmental medicine Ognibene, G. T., Torres, W., von Eyben, R., Horst, K. C. 2016; 58 (3): 287-293

    Abstract

    The aim of the study was to determine whether chronic low back pain (LBP) might be attenuated through the introduction of a sit-stand workstation (SSW) in office employees.Participants were randomized to receive a SSW at the beginning or at the end of a 3-month study period. Participants responded to a short survey at the end of each workday and a comprehensive survey at weeks 1, 6, and 12. Surveys consisted of a modified brief pain inventory and the Roland Morris Disability Questionnaire.Forty-six university employees with self-reported chronic LBP were enrolled. Participants who were given access to a SSW reported a significant reduction in current (P = 0.02) and worst (P = 0.04) LBP over time.Our findings support the hypothesis that chronic LBP might be improved by the introduction of a SSW in an office environment.

    View details for DOI 10.1097/JOM.0000000000000615

    View details for PubMedID 26735316

  • Fractionation of palliative radiotherapy in metastatic breast cancer: Selection and survival Qian, Y., Dudley, S., Durkee, B. Y., Kumar, K., Chaudhuri, A., Pollom, E. L., Aggarwal, S., Horst, K. C., Chang, D. AMER SOC CLINICAL ONCOLOGY. 2015
  • Trajectory Modulated Arc Therapy: A Fully Dynamic Delivery With Synchronized Couch and Gantry Motion Significantly Improves Dosimetric Indices Correlated With Poor Cosmesis in Accelerated Partial Breast Irradiation INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS Liang, J., Atwood, T., von Eyben, R., Fahimian, B., Chin, E., Horst, K., Otto, K., Hristov, D. 2015; 92 (5): 1148-1156

    Abstract

    To develop planning and delivery capabilities for linear accelerator-based nonisocentric trajectory modulated arc therapy (TMAT) and to evaluate the benefit of TMAT for accelerated partial breast irradiation (APBI) with the patient in prone position.An optimization algorithm for volumetrically modulated arc therapy (VMAT) was generalized to allow for user-defined nonisocentric TMAT trajectories combining couch rotations and translations. After optimization, XML scripts were automatically generated to program and subsequently deliver the TMAT plans. For 10 breast patients in the prone position, TMAT and 6-field noncoplanar intensity modulated radiation therapy (IMRT) plans were generated under equivalent objectives and constraints. These plans were compared with regard to whole breast tissue volume receiving more than 100%, 80%, 50%, and 20% of the prescription dose.For TMAT APBI, nonisocentric collision-free horizontal arcs with large angular span (251.5 ± 7.9°) were optimized and delivered with delivery time of ∼4.5 minutes. Percentage changes of whole breast tissue volume receiving more than 100%, 80%, 50%, and 20% of the prescription dose for TMAT relative to IMRT were -10.81% ± 6.91%, -27.81% ± 7.39%, -14.82% ± 9.67%, and 39.40% ± 10.53% (P≤.01).This is a first demonstration of end-to-end planning and delivery implementation of a fully dynamic APBI TMAT. Compared with IMRT, TMAT resulted in marked reduction of the breast tissue volume irradiated at high doses.

    View details for DOI 10.1016/j.ijrobp.2015.04.034

    View details for Web of Science ID 000357900600037

    View details for PubMedID 26050608

  • ACR Appropriateness Criteria (R) Ductal Carcinoma in Situ ONCOLOGY-NEW YORK Kaufman, S. A., Harris, E. E., Bailey, L., Chadha, M., Dutton, S. C., Freedman, G. M., Goyal, S., Halyard, M. Y., Horst, K. C., Novick, K. L., Park, C. C., Suh, W. W., Toppmeyer, D., Zook, J., Haffty, B. G. 2015; 29 (6): 446-?

    Abstract

    Ductal carcinoma in situ (DCIS) is a breast neoplasm with potential for progression to invasive cancer. Management commonly involves excision, radiotherapy, and hormonal therapy. Surgical assessment of regional lymph nodes is rarely indicated except in cases of microinvasion or mastectomy. Radiotherapy is employed for local control in breast conservation, although it may be omitted for select low-risk situations. Several radiotherapy techniques exist beyond standard whole-breast irradiation (ie, partial-breast irradiation [PBI], hypofractionated whole-breast radiation); evidence for these is evolving. We present an update of the American College of Radiology (ACR) Appropriateness Criteria® for the management of DCIS. The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions, which are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review includes an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi technique) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

    View details for Web of Science ID 000356842200010

    View details for PubMedID 26089220

  • Lymphopenia after adjuvant radiotherapy (RT) to predict poor survival in triple-negative breast cancer (TNBC). Afghahi, A., Mathur, M., Seto, T., Desai, M., Kenkare, P., Horst, K. C., Das, A. K., Thompson, C. A., Luft, H. S., Yu, P., Gomez, S., Low, Y., Shah, N. H., Kurian, A. W., Sledge, G. W. AMER SOC CLINICAL ONCOLOGY. 2015
  • Solid Malignancies in Individuals With Down Syndrome: A Case Presentation and Literature Review JOURNAL OF THE NATIONAL COMPREHENSIVE CANCER NETWORK Bratman, S. V., Horst, K. C., Carlson, R. W., Kapp, D. S. 2014; 12 (11): 1537-1545

    Abstract

    Individuals with Down syndrome (DS) are at elevated risk for acute leukemia, whereas solid tumors are uncommon, and most types, including breast cancers, have significantly lower-than-expected age-adjusted incidence rates. This article reports on a man with DS and breast cancer, thought to be the first in the literature, and presents the management of his cancer. The literature on malignancies in patients with DS is reviewed and the major epidemiologic studies that have examined the spectrum of cancer risk in individuals with DS are summarized. Potential environmental and genetic determinants of cancer risk are discussed, and the potential role of chromosomal mosaicism in cancer risk among patients with DS is explored. Trisomy of chromosome 21, which causes DS, provides an extra copy of genes with tumor suppressor or repressor functions. Recent studies have leveraged mouse and human genetics to uncover specific candidate genes on chromosome 21 that mediate these effects. In addition, global perturbations in gene expression programs have been observed, with potential effects on proliferation and self-renewal.

    View details for Web of Science ID 000344516200007

  • Solid malignancies in individuals with Down syndrome: a case presentation and literature review. Journal of the National Comprehensive Cancer Network Bratman, S. V., Horst, K. C., Carlson, R. W., Kapp, D. S. 2014; 12 (11): 1537-1545

    Abstract

    Individuals with Down syndrome (DS) are at elevated risk for acute leukemia, whereas solid tumors are uncommon, and most types, including breast cancers, have significantly lower-than-expected age-adjusted incidence rates. This article reports on a man with DS and breast cancer, thought to be the first in the literature, and presents the management of his cancer. The literature on malignancies in patients with DS is reviewed and the major epidemiologic studies that have examined the spectrum of cancer risk in individuals with DS are summarized. Potential environmental and genetic determinants of cancer risk are discussed, and the potential role of chromosomal mosaicism in cancer risk among patients with DS is explored. Trisomy of chromosome 21, which causes DS, provides an extra copy of genes with tumor suppressor or repressor functions. Recent studies have leveraged mouse and human genetics to uncover specific candidate genes on chromosome 21 that mediate these effects. In addition, global perturbations in gene expression programs have been observed, with potential effects on proliferation and self-renewal.

    View details for PubMedID 25361800

  • Breast magnetic resonance imaging alters patient selection for accelerated partial breast irradiation. American journal of clinical oncology Horst, K. C., Ikeda, D. M., Fero, K. E., Daniel, B. L., Goffinet, D. R., Dirbas, F. M. 2014; 37 (3): 248-254

    Abstract

    OBJECTIVES:: To determine whether pretreatment contrast-enhanced breast magnetic resonance imaging (MRI) alters patient selection for accelerated partial breast irradiation (APBI). MATERIALS AND METHODS:: Women aged 40 years or older with unifocal invasive or intraductal carcinoma ≤2.5 cm on physical examination, mammography, and ultrasound (US) were evaluated with breast MRI before enrollment on an APBI trial using single-fraction intraoperative radiotherapy (IORT) or fractionated 3-dimensional conformal radiotherapy. Abnormal MRI findings were evaluated with US-guided or MRI-guided biopsy. RESULTS:: Between December 2002 and March 2005, 51 women (median age=61 y; range, 40 to 83 y) who met inclusion criteria underwent breast MRI before APBI. MRI demonstrated limited disease in 41 patients (80.4%): 34 received APBI using IORT (22) or 3DCRT (12), whereas 7 elected standard whole-breast radiotherapy. Ten of the 51 patients (19.6%) had indeterminate or suspicious enhancement patterns on MRI. Five of these 10 (9.8% of MRI cohort) underwent US-guided or MRI-guided biopsy revealing normal breast tissue without atypia: 3 were treated with APBI using IORT (5.9% of MRI cohort) and 2 underwent standard breast conservation therapy (3.9% of MRI cohort). The remaining 5 patients (9.8% of MRI cohort) had MRI findings revealing previously unsuspected pectoral fascia involvement (1), multifocal disease (3), or multicentric disease (1): 2 were treated with standard breast conservation therapy, whereas 3 underwent mastectomy without adjuvant radiotherapy. CONCLUSIONS:: Pretreatment breast MRI altered patient selection for APBI by identifying additional disease in 9.8% of the candidates, all of whom fit into the "cautionary" or "unsuitable" categories as defined by the American Society for Radiation Oncology APBI consensus guidelines. The clinical significance of these findings will be clarified with the results of ongoing randomized trials of APBI that do not incorporate breast MRI as part of the selection criteria.

    View details for DOI 10.1097/COC.0b013e318277d7c8

    View details for PubMedID 23275271

  • Breast Magnetic Resonance Imaging Alters Patient Selection for Accelerated Partial Breast Irradiation AMERICAN JOURNAL OF CLINICAL ONCOLOGY-CANCER CLINICAL TRIALS Horst, K. C., Ikeda, D. M., Fero, K. E., Daniel, B. L., Goffinet, D. R., Dirbas, F. M. 2014; 37 (3): 248-254

    Abstract

    OBJECTIVES:: To determine whether pretreatment contrast-enhanced breast magnetic resonance imaging (MRI) alters patient selection for accelerated partial breast irradiation (APBI). MATERIALS AND METHODS:: Women aged 40 years or older with unifocal invasive or intraductal carcinoma ≤2.5 cm on physical examination, mammography, and ultrasound (US) were evaluated with breast MRI before enrollment on an APBI trial using single-fraction intraoperative radiotherapy (IORT) or fractionated 3-dimensional conformal radiotherapy. Abnormal MRI findings were evaluated with US-guided or MRI-guided biopsy. RESULTS:: Between December 2002 and March 2005, 51 women (median age=61 y; range, 40 to 83 y) who met inclusion criteria underwent breast MRI before APBI. MRI demonstrated limited disease in 41 patients (80.4%): 34 received APBI using IORT (22) or 3DCRT (12), whereas 7 elected standard whole-breast radiotherapy. Ten of the 51 patients (19.6%) had indeterminate or suspicious enhancement patterns on MRI. Five of these 10 (9.8% of MRI cohort) underwent US-guided or MRI-guided biopsy revealing normal breast tissue without atypia: 3 were treated with APBI using IORT (5.9% of MRI cohort) and 2 underwent standard breast conservation therapy (3.9% of MRI cohort). The remaining 5 patients (9.8% of MRI cohort) had MRI findings revealing previously unsuspected pectoral fascia involvement (1), multifocal disease (3), or multicentric disease (1): 2 were treated with standard breast conservation therapy, whereas 3 underwent mastectomy without adjuvant radiotherapy. CONCLUSIONS:: Pretreatment breast MRI altered patient selection for APBI by identifying additional disease in 9.8% of the candidates, all of whom fit into the "cautionary" or "unsuitable" categories as defined by the American Society for Radiation Oncology APBI consensus guidelines. The clinical significance of these findings will be clarified with the results of ongoing randomized trials of APBI that do not incorporate breast MRI as part of the selection criteria.

    View details for DOI 10.1097/COC.0b013e318277d7c8

    View details for Web of Science ID 000336958200006

  • Histologic subtypes of breast cancer following radiotherapy for Hodgkin lymphoma. Annals of oncology Horst, K. C., Hancock, S. L., OGNIBENE, G., Chen, C., Advani, R. H., Rosenberg, S. A., Donaldson, S. S., Hoppe, R. T. 2014; 25 (4): 848-851

    Abstract

    The purpose of the study was to determine whether breast cancers (BCs) that develop in women previously irradiated for Hodgkin lymphoma (HL) are biologically similar to sporadic BC.We retrospectively reviewed the charts of patients who developed BC after radiotherapy (RT) for HL. Tumors were classified as ductal carcinoma in situ (DCIS) or invasive carcinoma. Invasive carcinomas were further characterized according to the subtype: hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)-, HR+/HER2+, HR-/HER2+, and HR-/HER2-. BCs after HL were compared with four age-matched sporadic, non-breast cancer (BRCA) I or II mutated BCs.One hundred forty-seven HL patients who were treated with RT between 1966 and 1999 and subsequently developed BCs were identified. Of these, 65 patients with 71 BCs had complete pathologic information. The median age at HL diagnosis was 23 (range, 10-48). The median age at BC diagnosis was 44 (range, 28-66). The median time to developing BC was 20 years. Twenty cancers (28%) were DCIS and 51 (72%) were invasive. Of the 51 invasive cancers, 24 (47%) were HR+/HER2-, 2 (4%) were HR+/HER2+, 5 (10%) were HR-/HER2+, and 20 (39%) were HR-/HER2-. There were no differences in BC histologic subtype according to the age at which patients were exposed to RT, the use of chemotherapy for HL treatment, or the time from RT exposure to the development of BC. In a 4 : 1 age-matched comparison to sporadic BCs, BCs after HL were more likely to be HR-/HER2- (39% versus 14%) and less likely to be HR+/HER2- (47% versus 61%) or HR+/HER2+ (4% versus 14%) (P = 0.0003).BCs arising in previously irradiated breast tissue were more likely to be triple negative compared with age-matched sporadic invasive cancers and less likely to be HR positive. Further studies will be important to determine the molecular pathways of carcinogenesis in breast tissue that is exposed to RT.

    View details for DOI 10.1093/annonc/mdu017

    View details for PubMedID 24608191

  • Nonisocentric treatment strategy for breast radiation therapy: a proof of concept study. International journal of radiation oncology, biology, physics Li, R., Xing, L., Horst, K. C., Bush, K. 2014; 88 (4): 920-926

    Abstract

    To propose a nonisocentric treatment strategy as a special form of station parameter optimized radiation therapy, to improve sparing of critical structures while preserving target coverage in breast radiation therapy.To minimize the volume of exposed lung and heart in breast irradiation, we propose a novel nonisocentric treatment scheme by strategically placing nonconverging beams with multiple isocenters. As its name suggests, the central axes of these beams do not intersect at a single isocenter as in conventional breast treatment planning. Rather, the isocenter locations and beam directions are carefully selected, in that each beam is only responsible for a certain subvolume of the target, so as to minimize the volume of irradiated normal tissue. When put together, the beams will provide an adequate coverage of the target and expose only a minimal amount of normal tissue to radiation. We apply the nonisocentric planning technique to 2 previously treated clinical cases (breast and chest wall).The proposed nonisocentric technique substantially improved sparing of the ipsilateral lung. Compared with conventional isocentric plans using 2 tangential beams, the mean lung dose was reduced by 38% and 50% using the proposed technique, and the volume of the ipsilateral lung receiving ≥20 Gy was reduced by a factor of approximately 2 and 3 for the breast and chest wall cases, respectively. The improvement in lung sparing is even greater compared with volumetric modulated arc therapy.A nonisocentric implementation of station parameter optimized radiation therapy has been proposed for breast radiation therapy. The new treatment scheme overcomes the limitations of existing approaches and affords a useful tool for conformal breast radiation therapy, especially in cases with extreme chest wall curvature.

    View details for DOI 10.1016/j.ijrobp.2013.12.029

    View details for PubMedID 24606852

  • Nonisocentric treatment strategy for breast radiation therapy: a proof of concept study. International journal of radiation oncology, biology, physics Li, R., Xing, L., Horst, K. C., Bush, K. 2014; 88 (4): 920-926

    Abstract

    To propose a nonisocentric treatment strategy as a special form of station parameter optimized radiation therapy, to improve sparing of critical structures while preserving target coverage in breast radiation therapy.To minimize the volume of exposed lung and heart in breast irradiation, we propose a novel nonisocentric treatment scheme by strategically placing nonconverging beams with multiple isocenters. As its name suggests, the central axes of these beams do not intersect at a single isocenter as in conventional breast treatment planning. Rather, the isocenter locations and beam directions are carefully selected, in that each beam is only responsible for a certain subvolume of the target, so as to minimize the volume of irradiated normal tissue. When put together, the beams will provide an adequate coverage of the target and expose only a minimal amount of normal tissue to radiation. We apply the nonisocentric planning technique to 2 previously treated clinical cases (breast and chest wall).The proposed nonisocentric technique substantially improved sparing of the ipsilateral lung. Compared with conventional isocentric plans using 2 tangential beams, the mean lung dose was reduced by 38% and 50% using the proposed technique, and the volume of the ipsilateral lung receiving ≥20 Gy was reduced by a factor of approximately 2 and 3 for the breast and chest wall cases, respectively. The improvement in lung sparing is even greater compared with volumetric modulated arc therapy.A nonisocentric implementation of station parameter optimized radiation therapy has been proposed for breast radiation therapy. The new treatment scheme overcomes the limitations of existing approaches and affords a useful tool for conformal breast radiation therapy, especially in cases with extreme chest wall curvature.

    View details for DOI 10.1016/j.ijrobp.2013.12.029

    View details for PubMedID 24606852

  • ACR Appropriateness Criteria (R) Local-Regional Recurrence (LRR) and Salvage Surgery-Breast Cancer ONCOLOGY-NEW YORK Halyard, M. Y., Harris, E. E., Bailey, L., Freedman, G. M., Goyal, S., Horst, K. C., Moran, M. S., Park, C. C., Suh, W. W., Toppmeyer, D., Haffty, B. G. 2014; 28 (2): 157-?

    Abstract

    Although both breast-conserving surgery and mastectomy generally provide excellent local-regional control of breast cancer, local-regional recurrence (LRR) does occur. Predictors for LRR include patient, tumor, and treatment-related factors. Salvage after LRR includes coordination of available modalities, including surgery, radiation, chemotherapy, and hormonal therapy, depending on the clinical scenario. Management recommendations for breast cancer LRR, including patient scenarios, are reviewed, and represent evidence-based data and expert opinion of the American College of Radiology Appropriateness Criteria Expert Panel on LRR.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel.The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

    View details for Web of Science ID 000332265100013

  • Breast Cancer Treatment Across Health Care Systems CANCER Kurian, A. W., Mitani, A., Desai, M., Yu, P. P., Seto, T., Weber, S. C., Olson, C., Kenkare, P., Gomez, S. L., de Bruin, M. A., Horst, K., Belkora, J., May, S. G., Frosch, D. L., Blayney, D. W., Luft, H. S., Das, A. K. 2014; 120 (1): 103-111

    Abstract

    Understanding of cancer outcomes is limited by data fragmentation. In the current study, the authors analyzed the information yielded by integrating breast cancer data from 3 sources: electronic medical records (EMRs) from 2 health care systems and the state registry.Diagnostic test and treatment data were extracted from the EMRs of all patients with breast cancer treated between 2000 and 2010 in 2 independent California institutions: a community-based practice (Palo Alto Medical Foundation; "Community") and an academic medical center (Stanford University; "University"). The authors incorporated records from the population-based California Cancer Registry and then linked EMR-California Cancer Registry data sets of Community and University patients.The authors initially identified 8210 University patients and 5770 Community patients; linked data sets revealed a 16% patient overlap, yielding 12,109 unique patients. The percentage of all Community patients, but not University patients, treated at both institutions increased with worsening cancer prognostic factors. Before linking the data sets, Community patients appeared to receive less intervention than University patients (mastectomy: 37.6% vs 43.2%; chemotherapy: 35% vs 41.7%; magnetic resonance imaging: 10% vs 29.3%; and genetic testing: 2.5% vs 9.2%). Linked Community and University data sets revealed that patients treated at both institutions received substantially more interventions (mastectomy: 55.8%; chemotherapy: 47.2%; magnetic resonance imaging: 38.9%; and genetic testing: 10.9% [P < .001 for each 3-way institutional comparison]).Data linkage identified 16% of patients who were treated in 2 health care systems and who, despite comparable prognostic factors, received far more intensive treatment than others. By integrating complementary data from EMRs and population-based registries, a more comprehensive understanding of breast cancer care and factors that drive treatment use was obtained.

    View details for DOI 10.1002/cncr.28395

    View details for Web of Science ID 000328443000017

    View details for PubMedCentralID PMC3867595

  • Breast cancer treatment across health care systems: linking electronic medical records and state registry data to enable outcomes research. Cancer Kurian, A. W., Mitani, A., Desai, M., Yu, P. P., Seto, T., Weber, S. C., Olson, C., Kenkare, P., Gomez, S. L., de Bruin, M. A., Horst, K., Belkora, J., May, S. G., Frosch, D. L., Blayney, D. W., Luft, H. S., Das, A. K. 2014; 120 (1): 103-111

    Abstract

    Understanding of cancer outcomes is limited by data fragmentation. In the current study, the authors analyzed the information yielded by integrating breast cancer data from 3 sources: electronic medical records (EMRs) from 2 health care systems and the state registry.Diagnostic test and treatment data were extracted from the EMRs of all patients with breast cancer treated between 2000 and 2010 in 2 independent California institutions: a community-based practice (Palo Alto Medical Foundation; "Community") and an academic medical center (Stanford University; "University"). The authors incorporated records from the population-based California Cancer Registry and then linked EMR-California Cancer Registry data sets of Community and University patients.The authors initially identified 8210 University patients and 5770 Community patients; linked data sets revealed a 16% patient overlap, yielding 12,109 unique patients. The percentage of all Community patients, but not University patients, treated at both institutions increased with worsening cancer prognostic factors. Before linking the data sets, Community patients appeared to receive less intervention than University patients (mastectomy: 37.6% vs 43.2%; chemotherapy: 35% vs 41.7%; magnetic resonance imaging: 10% vs 29.3%; and genetic testing: 2.5% vs 9.2%). Linked Community and University data sets revealed that patients treated at both institutions received substantially more interventions (mastectomy: 55.8%; chemotherapy: 47.2%; magnetic resonance imaging: 38.9%; and genetic testing: 10.9% [P < .001 for each 3-way institutional comparison]).Data linkage identified 16% of patients who were treated in 2 health care systems and who, despite comparable prognostic factors, received far more intensive treatment than others. By integrating complementary data from EMRs and population-based registries, a more comprehensive understanding of breast cancer care and factors that drive treatment use was obtained.

    View details for DOI 10.1002/cncr.28395

    View details for PubMedID 24101577

    View details for PubMedCentralID PMC3867595

  • Trajectory modulated prone breast irradiation: A LINAC-based technique combining intensity modulated delivery and motion of the couch RADIOTHERAPY AND ONCOLOGY Fahimian, B., Yu, V., Horst, K., Xing, L., Hristov, D. 2013; 109 (3): 475-481

    Abstract

    External beam radiation therapy (EBRT) provides a non-invasive treatment alternative for accelerated partial breast irradiation (APBI), however, limitations in achievable dose conformity of current EBRT techniques have been correlated to reported toxicity. To enhance the conformity of EBRT APBI, a technique for conventional LINACs is developed, which through combined motion of the couch, intensity modulated delivery, and a prone breast setup, enables wide-angular coronal arc irradiation of the ipsilateral breast without irradiating through the thorax and contralateral breast.A couch trajectory optimization technique was developed to determine the trajectories that concurrently avoid collision with the LINAC and maintain the target within the MLC apertures. Inverse treatment planning was performed along the derived trajectory. The technique was experimentally implemented by programming the Varian TrueBeam™ STx in Developer Mode. The dosimetric accuracy of the delivery was evaluated by ion chamber and film measurements in phantom.The resulting optimized trajectory was shown to be necessarily non-isocentric, and contain both translation and rotations of the couch. Film measurements resulted in 93% of the points in the measured two-dimensional dose maps passing the 3%/3mm Gamma criterion. Preliminary treatment plan comparison to 5-field 3D-conformal, IMRT, and VMAT demonstrated enhancement in conformity, and reduction of the normal tissue V50% and V100% parameters that have been correlated with EBRT toxicity.The feasibility of wide-angular intensity modulated partial breast irradiation using motion of the couch has been demonstrated experimentally on a standard LINAC for the first time. For patients eligible for a prone setup, the technique may enable improvement of dose conformity and associated dose-volume parameters correlated with toxicity.

    View details for DOI 10.1016/j.radonc.2013.10.031

    View details for Web of Science ID 000329482000027

    View details for PubMedID 24231240

  • Defining an optimal role for breast magnetic resonance imaging when evaluating patients otherwise eligible for accelerated partial breast irradiation. Radiotherapy and oncology Horst, K. C., Fero, K. E., Ikeda, D. M., Daniel, B. L., Dirbas, F. M. 2013; 108 (2): 220-225

    Abstract

    BACKGROUND AND PURPOSE: Pre-treatment breast magnetic resonance imaging (MRI) findings in a cohort of women prospectively evaluated for accelerated partial breast irradiation (APBI) are reviewed and characterized to determine the optimal use of MRI in these patients. MATERIALS AND METHODS: Candidates initially deemed eligible for a prospective APBI trial based on physical examination, mammography, and ultrasound (US) were further evaluated with breast MRI before treatment. All abnormal MRI findings were biopsied. RESULTS: Between 2002 and 2011, 180 women who met inclusion criteria for APBI underwent breast MRI prior to treatment (median age=59; range 38-86). 126 tumors (70%) were invasive carcinomas with or without associated DCIS, while 54 (30%) were pure DCIS. Breast MRI confirmed unifocal disease in 109 patients with 111 cancers (60.5% of MRI cohort). Multifocal disease was identified in 19 patients (10.5% of MRI cohort), while multicentric disease was present in 3 patients (1.6% of MRI cohort). Five patients (4%) had an MRI-detected contralateral cancer. False positive MRI findings were seen in 45 patients (25% of MRI cohort). Pre-menopausal patients and patients with tumors >2cm were more likely to have MRI-detected multifocal/multicentric disease. While there was no statistically significant correlation between multifocal/multicentric disease and breast density, tumor histology, grade, ER status, or Her2/Neu expression, numbers in each category were small, suggesting a lack of statistical power to detect differences that may be clinically meaningful. One hundred and fifty-two of the 180 patients (84.4%) successfully completed lumpectomy and APBI, while 6.7% of the cohort underwent mastectomy. CONCLUSIONS: Breast MRI identified additional disease in 12% of APBI candidates. Premenopausal women and patients with tumors >2cm were more likely to have MRI-detected multifocal/multicentric disease.

    View details for DOI 10.1016/j.radonc.2013.01.019

    View details for PubMedID 23597699

  • Evolving trends in the initial locoregional management of male breast cancer BREAST Bratman, S. V., Kapp, D. S., Horst, K. C. 2012; 21 (3): 296-302

    Abstract

    The locoregional management of breast cancer in men has evolved over time. Multimodality treatment regimens currently in use are based primarily on large randomized trials that exclusively enrolled women with breast cancer. We retrospectively reviewed cases of male breast cancer treated with radiotherapy at Stanford University Medical Center with an emphasis on 22 patients treated with surgery and locoregional radiotherapy. We report trends in the surgical techniques as well as in the use of adjuvant radiotherapy, chemotherapy, and hormonal therapy. There were no isolated locoregional failures in this cohort, and 5-year disease-free survival was 65%. The use of contemporary surgical and radiotherapeutic techniques in men is discussed. We conclude that treatment guidelines designed for women should be applied to the locoregional management of breast cancer in men. However, large international prospective registries and inclusion of men in cooperative group randomized trials will be important to confirm the safety and efficacy of modern treatment modalities for male breast cancer.

    View details for DOI 10.1016/j.breast.2012.01.008

    View details for Web of Science ID 000306381500014

    View details for PubMedID 22321249

  • ACR Appropriateness Criterias (R) Local-regional Recurrence (LR) and Salvage Surgery Breast Cancer AMERICAN JOURNAL OF CLINICAL ONCOLOGY-CANCER CLINICAL TRIALS Halyard, M. Y., Wasif, N., Harris, E. E., Arthur, D. W., Bailey, L., Bellon, J. R., Carey, L., Goyal, S., Horst, K. C., Moran, M. S., MacDonald, S. M., Haffty, B. G. 2012; 35 (2): 178-182

    Abstract

    Despite the success of both breast conserving surgery and mastectomy, some women will experience a local-regional recurrence (LRR) of their breast cancer. Predictors for LRR after breast-conserving therapy or mastectomy have been identified, including patient, tumor, and treatment-related factors. The role of surgery, radiation, and chemotherapy as treatment has evolved over time and many patients now have the potential for salvage after LRR. This review of LRR of breast cancer and management recommendations, including the use of common clinical scenarios, represents a compilation of evidence-based data and expert opinion of the American College of Radiology Appropriateness Criteria Expert Panel on local-regional recurrence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

    View details for DOI 10.1097/COC.0b013e3182439084

    View details for Web of Science ID 000301956300016

    View details for PubMedID 22433995

  • ACR Appropriateness Criteria (R) Ductal Carcinoma in Situ BREAST JOURNAL Moran, M. S., Bai, H. X., Harris, E. E., Arthur, D. W., Bailey, L., Bellon, J. R., Carey, L., Goyal, S., Halyard, M. Y., Horst, K. C., MacDonald, S. M., Haffty, B. G. 2012; 18 (1): 8-15

    Abstract

    Ductal carcinoma in situ (DCIS) describes a wide spectrum of non-invasive tumors which carry a significant risk of invasive relapse, thus prevention of local recurrence is vital. For appropriate patients with limited disease, management with breast conserving surgery (BCS) followed by whole-breast radiation (RT) is supported by multiple Phase III studies, but mastectomy may be appropriate in selected patients. Omission of RT may also be reasonable in some patients, though which criteria are to be utilized remain unclear, and the existing data are contradictory with limited follow-up. Various RT techniques such as boost to the tumor bed, partial breast radiation or hypofractionated, whole-breast RT are increasingly utilized but the data to support their use specifically in DCIS is limited. Tamoxifen also increases local control for ER + DCIS, adding to the complexity of the local treatment management. This article reviews the existing scientific evidence, the controversies surrounding local management, and clinical guidelines for DCIS based on the group consensus by the ACR Breast Expert Panel. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

    View details for DOI 10.1111/j.1524-4741.2011.01197.x

    View details for Web of Science ID 000298916200003

    View details for PubMedID 22107336

  • ACR Appropriateness Criteria (R) Locally Advanced Breast Cancer BREAST JOURNAL MacDonald, S. M., Harris, E. E., Arthur, D. W., Bailey, L., Bellon, J. R., Carey, L., Goyal, S., Halyard, M. Y., Moran, M. S., Horst, K. C., Haffty, B. G. 2011; 17 (6): 579-585

    Abstract

    Locally advanced breast cancer (LABC) is a disease that is heterogeneous in its presentation, potentially curable, and generally necessitating multidisciplinary management. Radiation therapy (RT) plays an important role in the management of LABC. The integration of radiation with surgery, chemotherapy, and sometimes breast reconstruction can be complex. The American College of Radiology Appropriateness Criteria Breast Committee aims to provide guidance for the management of a variety of LABC cases. The American College of Radiology Appropriateness Criteria is evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is either lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

    View details for DOI 10.1111/j.1524-4741.2011.01150.x

    View details for Web of Science ID 000297104900003

    View details for PubMedID 21906206

  • ACR Appropriateness Criteria (R) Conservative surgery and Radiation - Stage I and II Breast Carcinoma BREAST JOURNAL Bellon, J. R., Harris, E. E., Arthur, D. W., Bailey, L., Carey, L., Goyal, S., Halyard, M. Y., Horst, K. C., Moran, M. S., MacDonald, S. M., Haffty, B. G. 2011; 17 (5): 448-455

    Abstract

    Breast conservation is a safe and effective alternative to mastectomy for the majority of women with early-stage breast cancer. Adjuvant radiation therapy lowers the risk of recurrence within the breast and also confers a survival benefit. Although acute side effects of radiation therapy are generally well tolerated; efforts are ongoing to minimize the long-term side effects of radiation, most prominently atherosclerotic heart disease. Efforts to minimize radiation therapy are also underway. They include omitting treatment altogether in the elderly and using accelerated, hypofractionated whole-breast irradiation, and accelerated partial-breast irradiation. Several randomized studies are ongoing to determine the efficacy, safety, and appropriate patients for these shorter treatments.

    View details for DOI 10.1111/j.1524-4741.2011.01132.x

    View details for Web of Science ID 000294979200002

    View details for PubMedID 21790842

  • Radiation Complications LYMPHEDEMA: A CONCISE COMPENDIUM OF THEORY AND PRACTICE Horst, K. C., Lee, B. B., Bergan, J., Rockson, S. G. 2011: 515–22
  • Accelerated, Partial Breast Irradiation with Intraoperative Radiotherapy BREAST SURGICAL TECHNIQUES AND INTERDISCIPLINARY MANAGEMENT Baynosa, J., Horst, K. C., Dirbas, F. M., Dirbas, F. M., ScottConner, C. E. 2011: 883–97
  • Breast Imaging Following Breast Conservation Therapy BREAST SURGICAL TECHNIQUES AND INTERDISCIPLINARY MANAGEMENT Gutierrez, R., Horst, K. C., Dirbas, F. M., Ikeda, D. M., Dirbas, F. M., ScottConner, C. E. 2011: 975–95
  • Accelerated, Partial Breast Irradiation Overview BREAST SURGICAL TECHNIQUES AND INTERDISCIPLINARY MANAGEMENT Wheeler, A. J., Dirbas, F. M., Horst, K. C., Dirbas, F. M., ScottConner, C. E. 2011: 829–36
  • Basic Principles of Radiobiology BREAST SURGICAL TECHNIQUES AND INTERDISCIPLINARY MANAGEMENT Horst, K. C., Giaccia, A. J., Dirbas, F. M., ScottConner, C. E. 2011: 799–811
  • MRI GUIDANCE FOR ACCELERATED PARTIAL BREAST IRRADIATION IN PRONE POSITION: IMAGING PROTOCOL DESIGN AND EVALUATION 50th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology (ASTRO) Ahn, K., Hargreaves, B. A., Alley, M. T., Horst, K. C., Luxton, G., Daniel, B. L., Hristov, D. ELSEVIER SCIENCE INC. 2009: 285–93

    Abstract

    To design and evaluate a magnetic resonance imaging (MRI) protocol to be incorporated in the simulation process for external beam accelerated partial breast irradiation.An imaging protocol was developed based on an existing breast MRI technique with the patient in the prone position on a dedicated coil. Pulse sequences were customized to exploit T1 and T2 contrast mechanisms characteristic of lumpectomy cavities. A three-dimensional image warping algorithm was included to correct for geometric distortions related to nonlinearity of spatially encoding gradients. Respiratory motion, image distortions, and susceptibility artifacts of 3.5-mm titanium surgical clips were examined. Magnetic resonance images of volunteers were acquired repeatedly to analyze residual setup deviations resulting from breast tissue deformation.The customized sequences generated high-resolution magnetic resonance images emphasizing lumpectomy cavity morphology. Respiratory motion was negligible with the subject in the prone position. The gradient-induced nonlinearity was reduced to less than 1 mm in a region 15 cm away from the isocenter of the magnet. Signal-void regions of surgical clips were 4 mm and 8 mm for spin echo and gradient echo images, respectively. Typical residual repositioning errors resulting from breast deformation were estimated to be 3 mm or less.MRI guidance for accelerated partial breast irradiation with the patient in the prone position with adequate contrast, spatial fidelity, and resolution is possible.

    View details for DOI 10.1016/j.ijrobp.2009.03.063

    View details for Web of Science ID 000269328700045

    View details for PubMedID 19632067

  • Phyllodes tumors of the breast: natural history, diagnosis, and treatment. Journal of the National Comprehensive Cancer Network Telli, M. L., Horst, K. C., Guardino, A. E., Dirbas, F. M., Carlson, R. W. 2007; 5 (3): 324-330

    Abstract

    Phyllodes tumors of the breast are unusual fibroepithelial tumors that exhibit a wide range of clinical behavior. These tumors are categorized as benign, borderline, or malignant based on a combination of histologic features. The prognosis of phyllodes tumors is favorable, with local recurrence occurring in approximately 15% of patients overall and distant recurrence in approximately 5% to 10% overall. Wide excision with a greater than 1 cm margin is definitive primary therapy. Adjuvant systemic therapy is of no proven value. Patients with locally recurrent disease should undergo wide excision of the recurrence with or without subsequent radiotherapy.

    View details for PubMedID 17439760

  • Association of clinical and pathologic variables with lumpectomy surgical margin status after preoperative diagnosis or excisional biopsy of invasive breast cancer ANNALS OF SURGICAL ONCOLOGY Smitt, M. C., Horst, K. 2007; 14 (3): 1040-1044

    Abstract

    To evaluate the impact of preoperative diagnosis in obtaining negative lumpectomy margins.Five hundred and thirty five patients who underwent breast conserving therapy for stage I/II cancer from 1971 to 1996 were included in this IRB-approved retrospective analysis. Three hundred and ninety five patients had a defined inked margin status after initial excision. The following factors were evaluated for correlation with margins at initial excision: age (< or >45), grade (3/1 or 2), family history (present/absent), histology (lobular/other), estrogen receptor (ER) status, presence of extensive intraductal carcinoma (EIC), presence of lymphovascular invasion (LVI), and biopsy type (excisional/preoperative).Biopsy type (P < 0.0001), EIC (P = 0.002), ER status (P = 0.02), lobular histology (P = 0.02) and age (P = 0.02) were significantly correlated with initial margin status among the entire group. For patients who underwent preoperative diagnostic biopsy, 52% (35/67) had negative initial margins as compared to 29% (94/328) for excisional biopsy. Among patients who underwent preoperative biopsy, only lobular histology (P = 0.04) and LVI (P = 0.04) were related to initial margin status. The rate of re-excision was 34% for patients diagnosed preoperatively versus 61% with excisional biopsy (P < 0.0001). The percentage of patients with negative final margin status was similar with either core/needle or excisional biopsy (79 and 78%, respectively).Preoperative diagnosis is the most significant predictor of initial margin status in patients undergoing breast conservation. Patients with lobular histology may require improved preoperative and/or intraoperative assessment to increase the rate of negative margins at initial excision.

    View details for DOI 10.1245/s10434-006-9308-1

    View details for Web of Science ID 000244820300008

    View details for PubMedID 17203329

  • Impact of increasing margin around the lumpectomy cavity to define the planning target volume for 3d conformal external beam accelerated partial breast irradiation 47th Annual Meeting of the American-Society-for-Therapeutic-Radiology-and-Oncology Cox, B. W., Horst, K. C., Thornton, S., Dirbas, F. M. ELSEVIER SCIENCE INC. 2007: 254–62

    Abstract

    The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.

    View details for DOI 10.1016/j.meddos.2007.02.003

    View details for Web of Science ID 000251075200004

    View details for PubMedID 17980825

  • Intraoperative Radiotherapy following Lumpectomy for Breast Cancer Semin Breast Dis Dirbas FM, Horst KC 2007; 10: 26-33
  • Association of Clinical and Pathologic Variables with Lumpectomy Surgical Margin Status after Preoperative Diagnosis or Excisional Biopsy of Invasive Breast Cancer Ann Surg Oncol Smitt MC, Horst K 2007; 14 (3): 1040-1044
  • Pathologic correlates of false positive breast magnetic resonance imaging findings: which lesions warrant biopsy? 6th Annual Meeting of the American-Society-of-Breast-Surgeons Langer, S. A., Horst, K. C., Ikeda, D. M., Daniel, B. L., Kong, C. S., Dirbas, F. M. EXCERPTA MEDICA INC-ELSEVIER SCIENCE INC. 2005: 633–40

    Abstract

    Contrast-enhanced breast magnetic resonance imaging (MRI) is highly sensitive for breast cancer. However, adoption of breast MRI is hampered by frequent false positive (FP) findings. Though ultimately proven benign, these suspicious findings require biopsy due to abnormal morphology and/or kinetic enhancement curves that simulate malignancy on MRI. We hypothesized that analysis of a series of FP MRI findings could reveal a pattern of association between certain "suspicious" lesions and benign disease that might help avoid unnecessary biopsy of such lesions in the future.A retrospective chart review identified women undergoing breast MRI between June 1995 and March 2002 with FP findings identified by MRI alone. Lesions were retrospectively characterized according to an MRI Breast Imaging-Reporting and Data System lexicon and matched to pathology.Twenty-two women were identified with 29 FP lesions. Morphology revealed 1 focus (3.5%), 5 masses less than 5 mm (17%), 11 masses greater than 5 mm (38%), 1 (3.5%) linear enhancement, and 11 (38%) non-mass-like enhancement. Kinetic curves were suspicious in 15 (52%). Histology demonstrated 20 (69%) variants of normal tissue and 9 (31%) benign masses. MRI lesions less than 5 mm (n = 6, 20.5%) were small, well-delineated nodules of benign breast tissue.Suspicious MRI lesions less than 5 mm often represent benign breast tissue and could potentially undergo surveillance instead of biopsy.

    View details for DOI 10.1016/j.amjsurg.2005.06.030

    View details for PubMedID 16164938

  • Predictors of local recurrence after breast-conservation therapy. Clinical breast cancer Horst, K. C., Smitt, M. C., Goffinet, D. R., Carlson, R. W. 2005; 5 (6): 425-438

    Abstract

    Breast-conserving therapy (BCT) is a proven local treatment option for select patients with early-stage breast cancer. This paper reviews pathologic, clinical, and treatment-related features that have been identified as known or potential predictors for ipsilateral breast tumor recurrence in patients treated with BCT. Pathologic risk factors such as the final pathologic margin status of the excised specimen after BCT, the extent of margin involvement, the interaction of margin status with other adverse features, the role of biomarkers, and the presence of an extensive intraductal component or lobular carcinoma in situ all impact the likelihood of ipsilateral breast tumor recurrence. Predictors of positive repeat excision findings after conservative surgery include young age, presence of an extensive intraductal component, and close or positive margins in prior excision. Finally, treatment-related factors predicting ipsilateral breast tumor recurrence include extent of breast radiation therapy, use of a boost to the lumpectomy cavity, use of tamoxifen or chemotherapeutic agents, and timing of systemic therapy with irradiation. The ability to predict for an increased risk of ipsilateral breast tumor recurrence enhances the ability to select optimal local treatment strategies for women considering BCT.

    View details for PubMedID 15748463

  • Predictors of Re-excision Findings and Ipsilateral Breast Tumor Recurrence after Breast Conservation Therapy Current Medical Literature Horst KC, Smitt MC, Goffinet DR 2004; 16 (4): 73-81