M. Usman Ahmad
Postdoctoral Scholar, General Surgery
Bio
Dr. Ahmad is currently a postdoctoral research fellow under the mentorship of Prof. George Poultsides in the Section of Surgical Oncology at Stanford University. In addition, he engages in basic scientific inquiry in tumor immunology under Prof. Amanda Kirane. As part of an interdisciplinary team, Dr. Ahmad is currently investigating the role of the intratumor microbiome and response to treatment for patients with pancreatic cancer funded by the Stanford Cancer Institute (SCI) and Sarafan ChEM-H. He entered his current position after completing 2 years of general surgical training at Stanford University and the University of Colorado.
Dr. Ahmad received his medical education at the University of South Florida (USF) where he was the recipient of numerous scholarships and awards including the Galen Scholarship, SELECT Koch Award, Anderson SELECT Scholarship, and Osler Award. During medical school, Dr. Ahmad was productive in both basic science and research resulting in 3 peer-reviewed publications and induction into the Robert A. Good Honor Society bestowed upon the top 10% of medical students in research. Dr. Ahmad also received the Alpha Omega Alpha Carolyn A. Kuckein Fellowship to continue policy work on improving the organ supply for Americans requiring organ transplants. Early in medical school, he conducted basic scientific work transplanting immune cells on metastatic melanoma in a mouse model while a visiting researcher under Prof. Gavin Pettigrew & Prof. Reza Mottalebzadeh in the Department of Surgery at the University of Cambridge in the United Kingdom. Dr. Ahmad was also active in health policy work culminating in a role as Vice Chair of the Medical Student Section Committee of Legislation & Advocacy for the American Medical Association with several roles at university, county, and state levels in both Florida and Pennsylvania. Dr. Ahmad has an extensive record of volunteer activity serving at risk populations in the United States during medical school including HIV, LGBTQ, pediatric, and homeless populations. In addition, he spends time mentoring and reviewing scholarship applications for Greenhouse Scholars, program focused on developing under-resourced high performing American students from high school to first career and beyond.
Prior to medical school, Dr. Ahmad had a career in the life sciences industry after receiving a degree in Economics from Northwestern University where he primarily focused on bringing new medical technology to market. Dr. Ahmad was part of a team selected by the Chicago Chamber of Commerce as the most innovative company in 2010 winning a state-wide competition. He also volunteered his time as a board member re-vitalizing a 25 year old arts organization in Chicago and helping to develop a business incubator in Detroit shortly after the Great Recession.
Dr. Ahmad is a native Chicagoan hailing from a large family raised near the Southside of Chicago. In his free time he enjoys cooking, reading, history, traveling, working on cars, and developing his interest in aviation.
All Publications
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Distal Pancreatectomy With and Without Celiac Axis Resection for Adenocarcinoma: A Comparison in the Era of Neoadjuvant Therapy
SPRINGER. 2024: S202-S203
View details for Web of Science ID 001185577500451
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Macrophage function over phenotype determines sensitization to immunotherapy
SPRINGER. 2024: S214
View details for Web of Science ID 001185577500478
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Toward the Development of Functional Biomarker Assays: Analysis of Neoadjuvant Intralesional Oncolytic Virus Response in High-Risk Stage II Melanoma
SPRINGER. 2024: S33-S34
View details for Web of Science ID 001185577500066
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Comprehensive assessment of immune context and immunotherapy response via noninvasive imaging in gastric cancer.
The Journal of clinical investigation
2024
Abstract
The tumor immune microenvironment can provide prognostic and therapeutic information. We aimed to develop noninvasive imaging biomarkers from computed tomography (CT) for comprehensive evaluation of immune context, and investigate their associations with prognosis and immunotherapy response in gastric cancer (GC).This study involved 2,600 GC patients of nine independent cohorts. We developed and validated two CT imaging biomarkers [lymphoid radiomics score (LRS) and myeloid radiomics score (MRS)] for evaluating the immunohistochemistry (IHC)-derived lymphoid and myeloid immune context respectively, and then integrated them into a combined imaging biomarker [LRS/MRS: low(-) or high(+)] with four radiomics immune subtypes: 1(-/-), 2(+/-), 3(-/+), and 4(+/+). We further evaluated the imaging biomarkers' predictive values on prognosis and immunotherapy response.The developed imaging biomarkers (LRS and MRS) had a high accuracy in predicting lymphoid (AUC range: 0.765-0.773) and myeloid (AUC range: 0.736-0.750) immune context. Furthermore, same as IHC-derived immune context, two imaging biomarkers (HR range: 0.240-0.761 for LRS; 1.301-4.012 for MRS) and the combined biomarker were independent predictors for disease-free and overall survival in the training and all validation cohorts (all P<0.05). In addition, patient with high LRS or low MRS may benefit more from immunotherapy (P<0.001). Furthermore, a highly heterogeneous outcome on objective response rate was observed in four imaging subtypes: 1(-/-) with 27.3%, 2(+/-) with 53.3%, 3(-/+) with 10.2%, and 4(+/+) with 30.0% (P<0.0001).The noninvasive imaging biomarkers could accurately evaluate the immune context, and provide information regarding prognosis and immunotherapy for GC.None.
View details for DOI 10.1172/JCI175834
View details for PubMedID 38271117
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Angioembolization for splenic injuries: does it help? Retrospective evaluation of grade III–V splenic injuries at two level I trauma centers
Trauma & Acute Care Open
2024; 9
View details for DOI 10.1136/tsaco-2023-001240
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Single cell analysis of melanoma reveals a prognostic myeloid cell associated with survival in melanoma with brain metastases
American Association for Cancer Research
2024
View details for DOI 10.1158/1538-7445.AM2024-6865
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Computational pathology approach for prognostic advancements and therapeutic benefits in gastrointestinal cancer: A multi-centric retrospective study
American Association for Cancer Research
2024
View details for DOI 10.1158/1538-7445.AM2024-4939
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Biology-guided deep learning predicts prognosis and cancer immunotherapy response.
Nature communications
2023; 14 (1): 5135
Abstract
Substantial progress has been made in using deep learning for cancer detection and diagnosis in medical images. Yet, there is limited success on prediction of treatment response and outcomes, which has important implications for personalized treatment strategies. A significant hurdle for clinical translation of current data-driven deep learning models is lack of interpretability, often attributable to a disconnect from the underlying pathobiology. Here, we present a biology-guided deep learning approach that enables simultaneous prediction of the tumor immune and stromal microenvironment status as well as treatment outcomes from medical images. We validate the model for predicting prognosis of gastric cancer and the benefit from adjuvant chemotherapy in a multi-center international study. Further, the model predicts response to immune checkpoint inhibitors and complements clinically approved biomarkers. Importantly, our model identifies a subset of mismatch repair-deficient tumors that are non-responsive to immunotherapy and may inform the selection of patients for combination treatments.
View details for DOI 10.1038/s41467-023-40890-x
View details for PubMedID 37612313
View details for PubMedCentralID PMC10447467
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Benchmarks and Geographic Differences in Gallbladder Cancer Surgery: An International Multicenter Study.
Annals of surgical oncology
2023
Abstract
BACKGROUND: High-quality surgery plays a central role in the delivery of excellent oncologic care. Benchmark values indicate the best achievable results. We aimed to define benchmark values for gallbladder cancer (GBC) surgery across an international population.PATIENTS AND METHODS: This study included consecutive patients with GBC who underwent curative-intent surgery during 2000-2021 at 13 centers, across seven countries and four continents. Patients operated on at high-volume centers without the need for vascular and/or bile duct reconstruction and without significant comorbidities were chosen as the benchmark group.RESULTS: Of 906 patients who underwent curative-intent GBC surgery during the study period, 245 (27%) were included in the benchmark group. These were predominantly women (n = 174, 71%) and had a median age of 64 years (interquartile range 57-70 years). In the benchmark group, 50 patients (20%) experienced complications within 90 days after surgery, with 20 patients (8%) developing major complications (Clavien-Dindo grade ≥ IIIa). Median length of postoperative hospital stay was 6 days (interquartile range 4-8 days). Benchmark values included ≥ 4 lymph nodes retrieved, estimated intraoperative blood loss ≤ 350 mL, perioperative blood transfusion rate ≤ 13%, operative time ≤ 332 min, length of hospital stay ≤ 8 days, R1 margin rate ≤ 7%, complication rate ≤ 22%, and rate of grade ≥ IIIa complications ≤ 11%.CONCLUSIONS: Surgery for GBC remains associated with significant morbidity. The availability of benchmark values may facilitate comparisons in future analyses among GBC patients, GBC surgical approaches, and centers performing GBC surgery.
View details for DOI 10.1245/s10434-023-13531-2
View details for PubMedID 37149547
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The Impact of Mesenchymal Transition and Macrophage Phenotype in Immunotherapy-Resistant Melanoma
SPRINGER. 2023: S236
View details for Web of Science ID 001046841200519
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The Role of AXL Tyrosine Kinase in the Melanoma Immune Microenvironment
SPRINGER. 2022: 465
View details for Web of Science ID 000789811800310
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Radiographic, Biochemical, or Pathologic Response to Neoadjuvant Chemotherapy in Resected Pancreatic Cancer: Which Is Best?
SPRINGER. 2022: 351
View details for Web of Science ID 000789811800041
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Neoadjuvant Intralesional Therapy for High Risk Stage II Melanoma
SPRINGER. 2022: 534
View details for Web of Science ID 000789811800468
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Neoadjuvant Treatment Strategies for Resectable Proximal Gastric, Gastroesophageal Junction and Distal Esophageal Cancer.
Cancers
2022; 14 (7)
Abstract
Neoadjuvant treatment strategies for resectable proximal gastric, gastroesophageal junction (GEJ), and distal esophageal cancer have evolved over several decades. Treatment recommendations differ based on histologic type-squamous cell carcinoma (SCC) versus adenocarcinoma (AC)-as well as the exact location of the tumor. Recent and older clinical trials in this area were critically reviewed. Neoadjuvant chemoradiation with concurrent taxane- or fluoropyrimidine-based chemotherapy has an established role for both AC and SCC of the distal esophagus and GEJ. The use of perioperative chemotherapy for gastric AC is based on the FLOT4 and MAGIC trials; however, the utility of neoadjuvant chemoradiation in this setting requires further evaluation. Additional clinical trials evaluating chemotherapy, targeted therapy, immunotherapy, and radiation that are currently in process are highlighted, given the need for further disease control.
View details for DOI 10.3390/cancers14071755
View details for PubMedID 35406527
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Rare histologies in peritoneal carcinomatosis: a narrative review
Digestive Medicine Research
2022; 5
View details for DOI 10.21037/dmr-22-4
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Biology-guided deep learning predicts prognosis and cancer immunotherapy response
Society for Immunotherapy of Cancer’s (SITC) 37th Annual Meeting
2022
View details for DOI 10.1136/jitc-2022-SITC2022.1284
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Acute Colonic Pseudo-Obstruction After Posterior Spinal Fusion: A Case Report and Literature Review
WORLD NEUROSURGERY
2020; 142: 352-363
Abstract
Acute colonic pseudo-obstruction (ACPO) or Ogilvie's syndrome occurs in 0.22%-7% of patients undergoing surgery, with a mortality of up to 46%. ACPO increased median hospital days versus control in spinal surgery (14 vs. 6 days; P < 0.001). If defined as postoperative ileus, the incidence was 7%-13.4%. Postoperative ileus is associated with 2.9 additional hospital days and an $80,000 increase in cost per patient. We present a case of ACPO in an adult patient undergoing spinal fusion for correction of scoliosis and review the available literature to outline clinical characteristics and surgical outcomes.The patient was a 31-year-old woman with untreated advanced scoliosis with no history of neurologic issues. T2-L3 spinal instrumentation and fusion was completed. Plain abdominal radiography showed of dilated cecum 11 cm and the department of general surgery was consulted. Neostigmine administration was planned after conservative treatment failure after transfer to the intensive care unit. The patient was discharged home with no recurrence >60 days. Thirty cases were found in our literature review using PubMed and Embase databases and summarized.Of 30 cases reviewed, only 3 cases of ACPO were specific to patients undergoing spinal fusion for scoliosis. According to the literature, 20% of patients had resolution with conservative treatment, 40% with neostigmine, and 30% with surgical intervention. Other noninvasive treatments may have similar efficacy in preventing complications leading to surgical invention. Sixty clinical trials and 9 systematic reviews were summarized with an updated management algorithm.
View details for DOI 10.1016/j.wneu.2020.07.013
View details for Web of Science ID 000576459300120
View details for PubMedID 32659357
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A predictive model for decreasing clinical no-show rates in a primary care setting
INTERNATIONAL JOURNAL OF HEALTHCARE MANAGEMENT
2021; 14 (3): 829-836
View details for DOI 10.1080/20479700.2019.1698864
View details for Web of Science ID 000501837900001
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A Systematic Review of Opt-out Versus Opt-in Consent on Deceased Organ Donation and Transplantation (2006-2016)
WORLD JOURNAL OF SURGERY
2019; 43 (12): 3161-3171
Abstract
Significant numbers of patients in the USA and UK die while waiting for solid organ transplant. Only 1-2% of deaths are eligible as donors with a fraction of the deceased donating organs. The form of consent to donation may affect the organs available. Forms of consent include: opt-in, mandated choice, opt-out, and organ conscription. Opt-in and opt-out are commonly practiced. A systematic review was conducted to determine the effect of opt-in versus opt-out consent on the deceased donation rate (DDR) and deceased transplantation rate (DTR).Literature searches of PubMed and EMBASE between 2006 and 2016 were performed. Research studies were selected based on certain inclusion criteria which include USA, UK, and Spain; compare opt-in versus opt-out; primary data analysis; and reported DDR or DTR. Modeled effect on US transplant activity was conducted using public data from Organ Procurement and Transplantation Network and Centers for Disease Control WONDER from 2006 to 2015.A total of 2400 studies were screened and six studies were included. Four studies reported opt-out consent increases DDR by 21-76% over 5-14 years. These studies compared 13-25 opt-out countries versus 9-23 opt-in countries. Three studies reported opt-out consent increases DTR by 38-83% over 11-13 years. These studies compared 22-25 opt-out versus 22-28 opt-in countries. Modeled opt-out activity on the USA resulted in 4753-17,201 additional transplants annually.Opt-out consent increases DDR and DTR and may be useful in decreasing deaths on the waiting list in the USA and other countries.PROSPERO CRD42019098759.
View details for DOI 10.1007/s00268-019-05118-4
View details for Web of Science ID 000501827500026
View details for PubMedID 31428836
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Clinical Activity of Nivolumab for Human Papilloma Virus-Related Juvenile-Onset Recurrent Respiratory Papillomatosis
ONCOLOGIST
2019; 24 (6): 829-835
Abstract
Juvenile-onset recurrent respiratory papillomatosis (JO-RRP) is a human papilloma virus-mediated progressive benign neoplasm that affects children and young adults. Primary management consists of regular surgical debulking to maintain airway patency and vocal function. Like condyloma acuminata, JO-RRP is associated with immune dysregulation, and T cells isolated from papillomas express an anergic phenotype. Therefore, we hypothesized that programmed death protein 1 axis inhibition could stabilize tumor growth.We treated two patients with refractory JO-RRP using nivolumab, with the primary objective of assessing clinical activity. We explored baseline papilloma features using immunohistochemistry and comprehensive genomic profiling.Both patients experienced symptomatic improvement, and interval laryngoscopies revealed a reduction in papillomatosis burden. One patient has not required subsequent surgical debridement for almost 2 years. On pathologic examination of pretreatment papillomas from both cases, infiltrating T cells were evident in the papilloma stroma, and papilloma programmed death ligand 1 expression was absent. Papilloma mutational load ranged between three and six mutations per megabase for each case. From on-treatment biopsy tissue, a higher amount of intraepithelial T cells and programmed death ligand 1 expression were detected in the papilloma.Nivolumab appears to have promising activity in JO-RRP, and further clinical investigation with more patients in clinical trials is warranted.To the authors' knowledge, this article is the first report describing clinical activity with a programed cell death-1 (PD-1) inhibitor to treat a rare but detrimental type of respiratory tract epithelial neoplasm that afflicts young adults. Two patients were treated, and tumor features, such as mutational load, were examined with the intent to stimulate future hypotheses for translational research. The safety and activity of PD-1 inhibitors in this population still need to be corroborated in clinical trials and should not yet be adopted into clinical practice.
View details for DOI 10.1634/theoncologist.2018-0505
View details for Web of Science ID 000471906300043
View details for PubMedID 30842242
View details for PubMedCentralID PMC6656512
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Increasing Organ Supply in the US: A Systematic Review of Presumed Consent vs. Informed Consent (2006-2016)
WILEY. 2017: 307
View details for Web of Science ID 000404515702285