Graduated from Medical School from Universidade de São Paulo (2013). Completed training in General Surgery (2016), Colorectal Surgery (2018), and doctorate in Gastroenterology at Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (2021).
Currently researching how the gut microbiome can affect patients' risk of developing complications after colorectal surgery, and whether it can be modulated by short-term dietary interventions.
Previous work focused on prevention and early treatment of anal and rectal cancer, and on the interaction between HPV infection and anal neoplasia.

Honors & Awards

  • The Chicago Society of Colon & Rectal Surgeons Best Basic Science Podium Presentation Award, American Society of Colon and Rectal Surgeons Annual Scientific Meeting (2020)
  • National Scholar Award - Brazil, United European Gastroenterology Week (2018)

Boards, Advisory Committees, Professional Organizations

  • International Member, Association of Women Surgeons (2021 - Present)
  • Member, International Anal Neoplasia Society (2021 - Present)
  • International Fellow, American Society of Colon and Rectal Surgeons (2019 - Present)
  • Member, Sociedade Brasileira de Coloproctologia (Brazilian Society of Coloproctology (2019 - Present)
  • Member, Colégio Brasileiro de Cirurgia Digestiva (Brazilian College of Digestive Surgery) (2019 - Present)

Stanford Advisors

All Publications

  • Magnifying chromoendoscopy is a reliable method in the selection of rectal neoplasms for local excision. Techniques in coloproctology Kimura, C. M., Kawaguti, F. S., Horvat, N., Nahas, C. S., Marques, C. F., Pinto, R. A., de Rezende, D. T., Segatelli, V., Safatle-Ribeiro, A. V., Junior, U. R., Maluf-Filho, F., Nahas, S. C. 2023


    PURPOSE: Adequate staging of early rectal neoplasms is essential for organ-preserving treatments, but magnetic resonance imaging (MRI) frequently overestimates the stage of those lesions. We aimed to compare the ability of magnifying chromoendoscopy and MRI to select patients with early rectal neoplasms for local excision.METHODS: This retrospective study in a tertiary Western cancer center included consecutive patients evaluated by magnifying chromoendoscopy and MRI who underwent en bloc resection of nonpedunculated sessile polyps larger than 20mm, laterally spreading tumors (LSTs) [Formula: see text] 20mm, or depressed-type lesions of any size (Paris 0-IIc). Sensitivity, specificity, accuracy, and positive and negative predictive values of magnifying chromoendoscopy and MRI to determine which lesions were amenable to local excision (i.e., [Formula: see text] T1sm1) were calculated.RESULTS: Specificity of magnifying chromoendoscopy was 97.3% (95% CI 92.2-99.4), and accuracy was 92.7% (95% CI 86.7-96.6) for predicting invasion deeper than T1sm1 (not amenable to local excision). MRI had lower specificity (60.5%, 95% CI 43.4-76.0) and lower accuracy (58.3%, 95% CI 43.2-72.4). Magnifying chromoendoscopy incorrectly predicted invasion depth in 10.7% of the cases in which the MRI was correct, while magnifying chromoendoscopy provided a correct diagnosis in 90% of the cases in which the MRI was incorrect (p=0.001). Overstaging occurred in 33.3% of the cases in which magnifying chromoendoscopy was incorrect and 75% of the cases in which MRI was incorrect.CONCLUSION: Magnifying chromoendoscopy is reliable for predicting invasion depth in early rectal neoplasms and selecting patients for local excision.

    View details for DOI 10.1007/s10151-023-02773-7

    View details for PubMedID 36906661

  • Salvage Surgery for Anal Squamous Cell Carcinoma: Still a Difficult Challenge. Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract de Paiva, A. C., Nahas, S. C., Kimura, C. M., Moniz, C. M., Marques, C. F., Junior, U. R., Nahas, C. S. 2022

    View details for DOI 10.1007/s11605-022-05486-8

    View details for PubMedID 36509896

  • Is It Really Gone? Assessing Response to Neoadjuvant Therapy in Rectal Cancer. Journal of gastrointestinal cancer Kimura, C., Crowder, S. E., Kin, C. 2022


    PURPOSE: Non-operative management of rectal cancer is a feasible and appealing treatment option for patients who develop a complete response after neoadjuvant therapy. However, identifying patients who are complete responders is often a challenge. This review aims to present and discuss current evidence and recommendations regarding the assessment of treatment response in rectal cancer.METHODS: A review of the current literature on rectal cancer restaging was performed. Studies included in this review explored the optimal interval between the end of neoadjuvant therapy and restaging, as well as modalities of assessment and their diagnostic performance.RESULTS: The current standard for restaging rectal cancer is a multimodal assessment with the digital rectal examination, endoscopy, and T2-weighted MRI with diffusion-weighted imaging. Other diagnostic procedures under investigation are PET/MRI, radiomics, confocal laser endomicroscopy, artificial intelligence-assisted endoscopy, cell-free DNA, and prediction models incorporating one or more of the above-mentioned exams.CONCLUSION: Non-operative management of rectal cancer requires a multidisciplinary approach. Understanding of the robustness and limitations of each exam is critical to inform patient selection for that treatment strategy.

    View details for DOI 10.1007/s12029-022-00889-x

    View details for PubMedID 36417142

  • Association of an Online Home-Based Prehabilitation Program With Outcomes After Colorectal Surgery. JAMA surgery Kimura, C. S., Bidwell, S., Gurland, B., Morris, A., Shelton, A., Kin, C. 2022


    This quality improvement study evaluates the association of an online home-based patient prehabilitation program with colorectal surgery outcomes.

    View details for DOI 10.1001/jamasurg.2022.4485

    View details for PubMedID 36322070

  • Mitigating Bias in Postoperative Pain Management: a Critical Piece of the Opioid Puzzle. World journal of surgery Kimura, C., Kin, C. 2022

    View details for DOI 10.1007/s00268-022-06554-5

    View details for PubMedID 35394229

  • Abdominal Surgery in Crohn's Disease: Risk Factors for Complications. Inflammatory intestinal diseases Sakurai Kimura, C. M., Scanavini Neto, A., Queiroz, N. S., Horvat, N., Camargo, M. G., Borba, M. R., Sobrado, C. W., Cecconello, I., Nahas, S. C. 2021; 6 (1): 18-24


    Abdominal surgery in patients with Crohn's disease (CD) is challenging, especially in the biologic era. The aim of this study was to evaluate factors associated with increased risk for postoperative complications in CD.A retrospective study was conducted with consecutive patients who underwent abdominal surgery for CD from January 2012 to January 2018.Of 103 patients, 32% had postoperative complications. Gender, age, disease location and phenotype, hemoglobin and albumin levels, previous abdominal surgery, and preoperative optimization did not differ between the groups with or without complications. Thirty-five percent of the patients were under anti-TNF therapy, and this medication was not associated with increased risk for postoperative complications. Time since the onset of the disease was significantly higher in patients with complications (12.9 vs. 9.4, p = 0.04). In multivariate analysis, creation of ostomy and urgent surgery were the only variables independently associated with increased risk for complications (OR 3.2, 95% CI 1.12-9.46 and OR 2.94, 95% CI 0.98-9.09, respectively).Urgent surgery for CD should preferably be performed in specialized centers, and creation of stoma is not necessarily associated with lower rate of postoperative complications but rather less severe complications.

    View details for DOI 10.1159/000510999

    View details for PubMedID 33850835

    View details for PubMedCentralID PMC8015258

  • High-risk human papillomavirus test in anal smears: can it optimize the screening for anal cancer? AIDS (London, England) Kimura, C. M., Nahas, C. S., Silva-Filho, E. V., Ribeiro, V. L., Segurado, A. C., Alcântara, F. F., Cecconello, I., Nahas, S. C. 2021; 35 (5): 737-745


    The current method for screening anal cancer is anal cytology, which has low sensitivity. Since high-risk human papillomavirus (HR-HPV) is associated with almost 90% of cases of anal cancer, the objective of this study is to evaluate whether testing for HR-HPV can optimize the screening.Prospective study with patients enrolled in a screening program for anal dysplasia. Considering high-resolution anoscopy (HRA)-guided biopsy as the gold standard for diagnosis of high-grade squamous intraepithelial lesions, the diagnostic performance of anal cytology, HR-HPV testing, and the combination of both was calculated.A single center for anal dysplasia.A total of 364 patients (72% males, 82% HIV-positive).Patients underwent anal cytology, HR-HPV test, and HRA-guided biopsy of the anal canal.Ability of cytology and HR-HPV test (individually and combined) to detect high-grade squamous intraepithelial lesions, and analysis of the cost of each diagnostic algorithm.Cytology alone was the cheapest approach, but had the lowest sensitivity [59%, 95% confidence interval (CI) 46-71%], despite of highest specificity (73%, 95% CI 68-78%). Cotesting had the highest sensitivity (85%, 95% CI 74-93%) and lowest specificity (43%, 95% CI 38-49%), and did not seem to be cost-effective. However, HR-HPV testing can be used to triage patients with normal and atypical squamous cells of undetermined significance cytology for HRA, resulting in an algorithm with high sensitivity (80%, 95% CI 68-89%), and specificity (71%, 95% CI 65-76%), allied to a good cost-effectiveness.HR-HPV testing is helpful to optimize the screening in cases of normal and atypical squamous cells of undetermined significance cytology.

    View details for DOI 10.1097/QAD.0000000000002795

    View details for PubMedID 33306557

  • Long-term outcomes of endoscopic submucosal dissection and transanal endoscopic microsurgery for the treatment of rectal tumors JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY Kimura, C., Kawaguti, F., Nahas, C., Marques, C., Segatelli, V., Martins, B., de Paulo, G., Cecconello, I., Ribeiro-Junior, U., Nahas, S., Maluf-Filho, F. 2021; 36 (6): 1634-1641


    Endoscopic submucosal dissection and transanal endoscopic microsurgery are good options for the treatment of rectal adenomas and early rectal carcinomas, but whether long-term outcomes of these procedures are comparable is not known. The aim of this study was to address this question.A retrospective single-center study evaluating 98 consecutive procedures between June 2008 and December 2017 was performed in a tertiary cancer center. Consecutive patients who had undergone either endoscopic submucosal resection or transanal endoscopic microsurgery for rectal adenomas and early rectal carcinomas were evaluated, and long-term recurrence and complication rates were compared.Both groups were similar regarding sex, age, preoperative surgical risk, and en bloc resection rate (95.7% in the endoscopic and 100% in the surgical group, P = 0.81). Mean follow-up period was 37.6 months. Lesions resected endoscopically were significantly larger (68.5 mm) than those resected by transanal resection (44.5 mm), P = 0.003. Curative resections occurred in 97.2% of endoscopic resections and 85.2% of the surgical ones (P = 0.04). Comparing resections that fulfilled histologic curative criteria, there were no recurrences in the endoscopic group (out of 69 cases) and two recurrences in the transanal group (8.3% of 24 cases), P = 0.06. Late complications occurred in 12.7% of endoscopic procedures and 25.9% of surgical procedures (P = 0.13).In our experience, endoscopic submucosal resection seems to have advantages over transanal endoscopic microsurgery, with similar en bloc resection rate and lower rate of late complications and recurrences. Multicenter randomized controlled trials are needed to support our findings.

    View details for DOI 10.1111/jgh.15309

    View details for Web of Science ID 000587978300001

    View details for PubMedID 33091219



    Knowing esophageal tumors behavior in relationship to lymph node involvement, distant metastases and local tumor invasion is of paramount importance for the best esophageal tumors management.To describe lymph node involvement, distant metastases, and local tumor invasion in esophageal carcinoma, according to tumor topography and histology.A total of 444 patients with esophageal squamous cell carcinoma and 105 adenocarcinoma were retrospectively analyzed. They were divided into four groups: adenocarcinoma and squamous cell carcinoma in the three esophageal segments: cervical, middle, and distal. They were compared based on their CT scans at the time of the diagnosis.Nodal metastasis showed great relationship with of primary tumor site. Lymph nodes of hepatogastric, perigastric and peripancreatic ligaments were mainly affected in distal tumors. Periaortic, interaortocaval and portocaval nodes were more commonly found in distal squamous carcinoma; subcarinal, paratracheal and subaortic nodes in middle; neck chains were more affected in cervical squamous carcinoma. Adenocarcinoma had a higher frequency of peritoneal involvement (11.8%) and liver (24.5%) than squamous cell carcinoma. Considering the local tumor invasion, the more cranial neoplasia, more common squamous invasion of airways, reaching 64.7% in the incidence of cervical tumors. Middle esophageal tumors invade more often aorta (27.6%) and distal esophageal tumors, the pericardium and the right atrium (10.4%).Esophageal adenocarcinoma and squamous cell carcinoma in different topographies present peculiarities in lymph node involvement, distant metastasis and local tumor invasion. These differences must be taken into account in esophageal cancer patients' care.

    View details for DOI 10.1590/0102-6720201600040001

    View details for Web of Science ID 000392703900001

    View details for PubMedID 28076472

    View details for PubMedCentralID PMC5225857



    Despite recent advances in diagnosis and treatment, esophageal cancer still has high mortality. Prognostic factors associated with patient and with disease itself are multiple and poorly explored.Assess prognostic variables in esophageal cancer patients.Retrospective review of all patients with esophageal cancer in an oncology referral center. They were divided according to histological diagnosis (444 squamous cell carcinoma patients and 105 adenocarcinoma), and their demographic, pathological and clinical characteristics were analyzed and compared to clinical stage and overall survival.No difference was noted between squamous cell carcinoma and esophageal adenocarcinoma overall survival curves. Squamous cell carcinoma presented 22.8% survival after five years against 20.2% for adenocarcinoma. When considering only patients treated with curative intent resection, after five years squamous cell carcinoma survival rate was 56.6 and adenocarcinoma, 58%. In patients with squamous cell carcinoma, poor differentiation histology and tumor size were associated with worse oncology stage, but this was not evidenced in adenocarcinoma.Weight loss (kg), BMI variation (kg/m²) and percentage of weight loss are factors that predict worse stage at diagnosis in the squamous cell carcinoma. In adenocarcinoma, these findings were not statistically significant.

    View details for DOI 10.1590/0102-6720201600030003

    View details for Web of Science ID 000389209300003

    View details for PubMedID 27759773

    View details for PubMedCentralID PMC5074661

  • ESOPHAGEAL CARCINOMA: IS SQUAMOUS CELL CARCINOMA DIFFERENT DISEASE COMPARED TO ADENOCARCINOMA? A transversal study in a quaternary high volume hospital in Brazil. Arquivos de gastroenterologia Tustumi, F., Takeda, F. R., Kimura, C. M., Sallum, R. A., Ribeiro, U., Cecconello, I. 2015; 53 (1): 44-8


    Esophageal cancer is one of the leading causes of mortality among the neoplasms that affect the gastrointestinal tract. There are several factors that contribute for development of an epidemiological esophageal cancer profile in a population.This study aims to describe both clinically and epidemiologically the population of patients with diagnosis of esophageal cancer treated in a quaternary attention institute for cancer from January, 2009 to December, 2011, in Sao Paulo, Brazil.The charts of all patients diagnosed with esophageal cancer from January, 2009, to December, 2011, in a Sao Paulo (Brazil) quaternary oncology institute were retrospectively reviewed.Squamous cell cancer made up to 80% of the cases of esophageal cancer. Average age at diagnosis was 60.66 years old for esophageal adenocarcinoma and 62 for squamous cell cancer, average time from the beginning of symptoms to the diagnosis was 3.52 months for esophageal adenocarcinoma and 4.2 months for squamous cell cancer. Average time for initiating treatment when esophageal cancer is diagnosed was 4 months for esophageal adenocarcinoma and 4.42 months for squamous cell cancer. There was a clear association between squamous cell cancer and head and neck cancers, as well as certain habits, such as smoking and alcoholism, while adenocarcinoma cancer showed more association with gastric cancer and gastroesophageal reflux disease. Tumoral bleeding and pneumonia were the main causes of death. No difference in survival rate was noted between the two groups.Adenocarcinoma and squamous cell carcinoma are different diseases, but both are diagnosed in advanced stages in Brazil, compromising the patients' possibilities of cure.

    View details for DOI 10.1590/S0004-28032016000100009

    View details for PubMedID 27281504