M. Usman Ahmad

Dr. M. Usman Ahmad

Stanford University, Stanford, California, USA
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 August 2023 in Nature Communications
Verified
Journal Article
Open access
PDF file
YJYuming Jiang
Yuming Jiang
ZZZhicheng Zhang
Zhicheng Zhang
WWwei wang
wei wang
WHWeicai Huang
Weicai Huang
CCChuanli Chen
Chuanli Chen
RLRuijiang Li
Ruijiang Li
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.

19 August 2019 in World Journal of Surgery
Verified
Journal Article
Closed access
PDF file
MAM. Usman Ahmad
M. Usman Ahmad
AHAfif Hanna
Afif Hanna
AMAhmed‐Zayn Mohamed
Ahmed‐Zayn Mohamed
ASAlex Schlindwein
Alex Schlindwein
CPCaitlin Pley
Caitlin Pley
TJTambi Jarmi
Tambi Jarmi

16 January 2024 in Journal of Clinical Investigation
Verified
Journal Article
Open access
PDF file
ZSzepang sun
zepang sun
TZTaojun Zhang
Taojun Zhang
MAM. Usman Ahmad
M. Usman Ahmad
ZZZixia Zhou
Zixia Zhou
LQLiang Qiu
Liang Qiu
YJYuming Jiang
Yuming Jiang
BACKGROUND: 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). METHODS: This study involved 2,600 patients with GC from 9 independent cohorts. We developed and validated 2 CT imaging biomarkers (lymphoid radiomics score [LRS] and myeloid radiomics score [MRS]) for evaluating the IHC-derived lymphoid and myeloid immune context respectively, and integrated them into a combined imaging biomarker [LRS/MRS: low(−) or high(+)] with 4 radiomics immune subtypes: 1 (−/−), 2 (+/−), 3 (−/+), and 4 (+/+). We further evaluated the imaging biomarkers’ predictive values on prognosis and immunotherapy response. RESULTS: 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. Further, similar to the IHC-derived immune context, 2 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). Additionally, patients with high LRS or low MRS may benefit more from immunotherapy ( P < 0.001). Further, a highly heterogeneous outcome on objective response rate was observed in 4 imaging subtypes: 1 (−/−) with 27.3%, 2 (+/−) with 53.3%, 3 (−/+) with 10.2%, and 4 (+/+) with 30.0% ( P < 0.0001). CONCLUSION: The noninvasive imaging biomarkers could accurately evaluate the immune context and provide information regarding prognosis and immunotherapy for GC.

9 December 2019 in International Journal of Healthcare Management
Verified
Journal Article
Closed access
MAM. Usman Ahmad
M. Usman Ahmad
AZAngie Zhang
Angie Zhang
RMRahul Mhaskar
Rahul Mhaskar
A challenging obstacle to primary health care in the United States (US) is patient no-shows or missed appointments. The no-show rate can vary from 5.5% to 50%. A no-show may contribute to increased health risks, poor continuity of care, and loss of revenue. In this study, we develop and test a predictive model of patient visits. Retrospective regression analyzed patient visits in 2014 and 2015. Dependent variables were month, day, age, gender, race, ethnicity, insurance type, visit type, and the number of previous no-shows. A threshold for classifying no-shows was determined. The model was prospectively tested on patient visits in 2016. Significant variables included age, visit type, insurance, and number of previous no-shows. The model performed at 47% sensitivity and 79% specificity. The receiver operating characteristic (ROC) area under curve (AUC) was 0.72 (95% CI, 0.69–0.76) for the model and 0.70 (95% CI, 0.65–0.74) for prospective analysis. Simulated overbooking with the model resulted in 3.67 vs. 6.87 unused appointments, P < 0.000 (mean diff 3.2, 95% CI, 2.9–3.5). It is feasible to develop and implement a predictive model for single physician practices and implementation may improve practice efficiency.

15 July 2025 in Cancer Letters
Verified
Journal Article
Open access
WHWeicai Huang
Weicai Huang
XWXiaoyan Wang
Xiaoyan Wang
RZRou Zhong
Rou Zhong
ZLZhe Li
Zhe Li
KZKangneng Zhou
Kangneng Zhou
YJYuming Jiang
Yuming Jiang
Immunotherapy has become a cornerstone in the treatment of advanced gastric cancer (GC). However, identifying reliable predictive biomarkers remains a considerable challenge. This study demonstrates the potential of integrating multimodal baseline data, including computed tomography scan images and digital H&E-stained pathology images, with biological interpretation to predict the response to immunotherapy-based combination therapy using a multicenter cohort of 298 GC patients. By employing seven machine learning approaches, we developed a radiopathomics signature (RPS) to predict treatment response and stratify prognostic risk in GC. The RPS demonstrated area under the receiver-operating-characteristic curves (AUCs) of 0.978 (95 % CI, 0.950-1.000), 0.863 (95 % CI, 0.744-0.982), and 0.822 (95 % CI, 0.668-0.975) in the training, internal validation, and external validation cohorts, respectively, outperforming conventional biomarkers such as CPS, MSI-H, EBV, and HER-2. Kaplan-Meier analysis revealed significant differences of survival between high- and low-risk groups, especially in advanced-stage and non-surgical patients. Additionally, genetic analyses revealed that the RPS correlates with enhanced immune regulation pathways and increased infiltration of memory B cells. The interpretable RPS provides accurate predictions for treatment response and prognosis in GC and holds potential for guiding more precise, patient-specific treatment strategies while offering insights into immune-related mechanisms.

17 June 2024 in International Journal of Surgery
Verified
Journal Article
Open access
YCYan Chen
Yan Chen
ZSzepang sun
zepang sun
JYJunmei Yin
Junmei Yin
MAM. Usman Ahmad
M. Usman Ahmad
ZZZixia Zhou
Zixia Zhou
YJYuming Jiang
Yuming Jiang
Background: Tertiary lymphoid structures (TLSs) are associated with favorable prognosis and enhanced response to anticancer therapy. A digital assessment of TLSs could provide an objective alternative that mitigates variability inherent in manual evaluation. This study aimed to develop and validate a digital gene panel based on biological prior knowledge for assessment of TLSs, and further investigate its associations with survival and multiple anticancer therapies. Materials and methods: The present study involved 1704 patients with gastric cancer from seven cancer centers. TLSs were identified morphologically through hematoxylin-and-eosin staining. The authors further developed a digital score based on targeted gene expression profiling to assess TLSs status, recorded as gene signature of tertiary lymphoid structures (gsTLS). For enhanced interpretability, we employed the SHapley Additive exPlanation (SHAP) analysis to elucidate its contribution to the prediction. The authors next evaluated the signature’s associations with prognosis, and investigated its predictive accuracy for multiple anticancer therapies, including adjuvant chemotherapy and immunotherapy. Results: The gsTLS panel with nine gene features achieved high accuracies in predicting TLSs status in the training, internal, and external validation cohorts (area under the curve, range: 0.729–0.791). In multivariable analysis, gsTLS remained an independent predictor of disease-free and overall survival (hazard ratio, range: 0.346–0.743, all P<0.05) after adjusting for other clinicopathological variables. SHAP analysis highlighted gsTLS as the strongest predictor of TLSs status compared with clinical features. Importantly, patients with high gsTLS (but not those with low gsTLS) exhibited substantial benefits from adjuvant chemotherapy (P<0.05). Furthermore, the authors found that the objective response rate to antiprogrammed cell death protein 1 (anti-PD-1) immunotherapy was significantly higher in the high-gsTLS group (40.7%) versus the low-gsTLS group (5.6%, P=0.036), and the diagnosis was independent from Epstein–Barr virus, tumor mutation burden, and programmed cell death-ligand 1 (PD-L1) expression. Conclusion: The gsTLS digital panel enables accurate assessment of TLSs status, and provides information regarding prognosis and responses to multiple therapies for gastric cancer.