Nathanael R. Fillmore
Topics / Patient Outcomes
Topic

Patient Outcomes

Fillmore has extensively investigated the determinants of survival and morbidity in patients with malignancies, with a particular focus on the impact of frailty, multimorbidity, and socioeconomic disparities. His research has identified critical prognostic biomarkers, such as lymphocyte and platelet counts, and developed machine learning risk scores to predict cardiovascular events and venous thromboembolism in oncology populations. Additionally, his work demonstrates that while equal access to healthcare can mitigate some racial disparities in survival, social determinants and functional status remain primary drivers of clinical outcomes.

U.S. Veterans and VA Data 31 Retrospective Cohort Study 23 Real World Evidence 19 Overall Survival 18 Survival Analysis 16 Cox Proportional Hazards Model 11 Electronic Health Records 9 Cancer Patients 8 Risk Stratification 8 Frailty 7 Multiple Myeloma 7 Hematologic Malignancies 7

Publications (32)

2026

Sentinel lymph node biopsy utilization and positivity in veterans with cutaneous melanoma: A comparative analysis of the VA Cancer Registry and the SEER Program.

Daniel Y. Kim, Susan M. Swetter, Linden Huhmann, Jacqueline M. Ferguson, Kimberly Breglio, Allyson C. Spence, Lee Wheless, Mary T. Brophy, Nhan V. Do, Nathanael Fillmore‡, Rebecca I. Hartman‡‡ Equal senior authorship

Journal of the American Academy of Dermatology
U.S. Veterans and VA Data Cutaneous Melanoma VA Cancer Registry SEER Database Sentinel Lymph Node Biopsy
2026

Association of Frailty With Transfusions, Hospitalizations, and Survival in Patients With Myelodysplastic Syndrome Initiating Hypomethylating Agents.

Anahid Hamparsumian†, Jennifer La†, Mayuri Dharne, Gary Gilbert, Mary T. Brophy, Nhan V. Do, Dae Hyun Kim, Jane A. Driver, Nathanael R. Fillmore‡, Clark DuMontier‡† Equal first authorship · ‡ Equal senior authorship

EJHaem7(4), e70352
U.S. Veterans and VA Data Retrospective Cohort Study Frailty Overall Survival Hospitalization Metrics
2026

Frailty and survival outcomes in veterans with invasive cutaneous melanoma: A Veterans Affairs Cancer Registry retrospective cohort study.

Linden B. Huhmann†, Jonathan C. Hwang†, Daniel Y. Kim, Kaelyn Nannini, Nhan V. Do, John M. Gaziano, Lee E. Wheless, Nathanael R. Fillmore‡, Rebecca I. Hartman‡† Equal first authorship · ‡ Equal senior authorship

Journal of the American Academy of Dermatology95(1), 240-243
U.S. Veterans and VA Data Retrospective Cohort Study Cancer-Associated Thrombosis Cutaneous Melanoma Overall Survival
2026

Development and External Validation of a Machine Learning-Based Risk Classification Score for Prostate Cancer-Specific Cardiovascular Risk.

Nickolas Stabellini, Tarek Nahle, Viraj Shah, Sai S. Kollapaneni, Omar M. Makram, Jennifer Cullen, Neal L. Weintraub, Harikrishnan H. Kunhiraman, Umang Swami, Morteza Mahmoudi, Nathanael Fillmore, Isla P. Garraway, Darryl Leong, Jehonathan Pinthus, John Shanahan, Alberto J. Montero, Neeraj Agarwal, Avirup Guha

JCO Oncology PracticeOP2600131
Prostate Cancer Cardiovascular Disease Cardio-Oncology Machine Learning Predictive Modeling
2025

Potentially Inappropriate Medications, Frailty, and Outcomes in Patients With Cancer Managed in a National Health Care System.

Jennifer La, Tammy Hshieh, Anahid Hamparsumian, Robert Zwolinski, Jameson Wood, Mayuri Dharne, J. Michael Gaziano, Mary T. Brophy, Nhan V. Do, Nikhil C. Munshi, Jane A. Driver, Gregory A. Abel, Nathanael R. Fillmore‡, Clark DuMontier‡‡ Equal senior authorship

Journal of the National Comprehensive Cancer Network23(9), 363-370
U.S. Veterans and VA Data Retrospective Cohort Study Electronic Health Records Frailty Overall Survival
2025

Multimorbidity and Its Impact in Older U.S. Veterans Newly Treated for Advanced Non-Small Cell Lung Cancer.

Joseph R. Larsen†, Chunlei Zheng†, Jennifer La, Julie Tsu-Yu Wu, Michael Kelley, J. Michael Gaziano, Mary Brophy, Nhan V. Do, Dae H. Kim, Jane A. Driver, Clark DuMontier‡, Nathanael R. Fillmore‡† Equal first authorship · ‡ Equal senior authorship

Annals of the American Thoracic Society22(4), 598-608
U.S. Veterans and VA Data Retrospective Cohort Study Lung Cancer Overall Survival Geriatric Oncology
2025

Leveraging near-real-time patient and population data to incorporate fluctuating risk of severe COVID-19: development and prospective validation of a personalised risk prediction tool.

Kaitlin Swinnerton†, Nathanael R. Fillmore†, Austin Vo, Jennifer La, Danne Elbers, Mary Brophy, Nhan V. Do, Paul A. Monach‡, Westyn Branch-Elliman‡† Equal first authorship · ‡ Equal senior authorship

eClinicalMedicine81, 103114
U.S. Veterans and VA Data Retrospective Cohort Study COVID-19 Severe COVID-19 Predictive Modeling
2024

Thrombosis risk prediction in lymphoma patients: A multi-institutional, retrospective model development and validation study.

Shengling Ma†, Jennifer La†, Kaitlin N. Swinnerton, Danielle Guffey, Raka Bandyo, Las Pozas Giordana De, Katy Hanzelka, Xiangjun Xiao, Cristhiam M. Rojas-Hernandez, Christopher I. Amos, Vipul Chitalia, Katya Ravid, Kelly W. Merriman, Christopher R. Flowers, Nathanael Fillmore‡, Ang Li‡† Equal first authorship · ‡ Equal senior authorship

American Journal of Hematology99(7), 1230-1239
U.S. Veterans and VA Data Retrospective Cohort Study Cancer-Associated Thrombosis Lymphoma Predictive Modeling
2024

Brain tumors in United States military veterans.

John R. Bihn†, Gino Cioffi†, Kristin A. Waite, Carol Kruchko, Corey Neff, Mackenzie Price, Quinn T. Ostrom, Kaitlin N. Swinnerton, Danne C. Elbers, Michael A. Mooney, Jacob Rachlin, Thor D. Stein, Mary T. Brophy, Nhan V. Do, Ryan E. Ferguson, David S. Priemer, Daniel P. Perl, Richard A. Hickman, Burt Nabors, Jennifer Rusiecki, Jill S. Barnholtz-Sloan‡, Nathanael R. Fillmore‡† Equal first authorship · ‡ Equal senior authorship

Neuro-oncology26(2), 387-396
U.S. Veterans and VA Data Primary Brain Tumors Overall Survival VA Cancer Registry Epidemiology
2023

Derivation and Validation of a Clinical Risk Assessment Model for Cancer-Associated Thrombosis in Two Unique US Health Care Systems.

Ang Li†, Jennifer La†, Sarah B. May, Danielle Guffey, Costa Wilson L. da, Christopher I. Amos, Raka Bandyo, Emily M. Milner, Karen M. Kurian, Daniel C. R. Chen, Nhan V. Do, Carolina Granada, Nimrah Riaz, Mary T. Brophy, Vipul Chitalia, J. Michael Gaziano, David A. Garcia, Marc Carrier, Christopher R. Flowers, Neil A. Zakai‡, Nathanael R. Fillmore‡† Equal first authorship · ‡ Equal senior authorship

Journal of Clinical Oncology41(16), 2926-2938
Cancer-Associated Thrombosis Predictive Modeling Retrospective Cohort Study External Validation U.S. Veterans and VA Data
2023

Epidemiology of Cancer-Associated Venous Thromboembolism in Patients With Solid and Hematologic Neoplasms in the Veterans Affairs Health Care System.

Kylee L. Martens†, Ang Li†, Jennifer La, Sarah B. May, Kaitlin N. Swinnerton, Hannah Tosi, Danne C. Elbers, Nhan V. Do, Mary T. Brophy, J. Michael Gaziano, Saran Lotfollahzadeh, Vipul Chitalia, Katya Ravid, Nathanael R. Fillmore† Equal first authorship

JAMA Network Open6(6), e2317945
U.S. Veterans and VA Data Retrospective Cohort Study Electronic Health Records Cancer-Associated Thrombosis Health Disparities
2023

Allostatic load and cardiovascular outcomes in males with prostate cancer.

Nickolas Stabellini, Jennifer Cullen, Marcio S. Bittencourt, Justin X. Moore, Lifen Cao, Neal L. Weintraub, Ryan A. Harris, Xiaoling Wang, Biplab Datta, Steven S. Coughlin, Jorge Garcia, John Shanahan, Nelson Hamerschlak, Kristin Waite, Nathanael R. Fillmore, Martha Terris, Alberto J. Montero, Jill S. Barnholtz-Sloan‡, Avirup Guha‡‡ Equal senior authorship

JNCI Cancer Spectrum7(2)
Allostatic Load Cardiovascular Disease Major Adverse Cardiovascular Events Prostate Cancer Fine-Gray Models
2021

Defining Multimorbidity and Its Impact in Older United States Veterans Newly Treated for Multiple Myeloma.

Nathanael R. Fillmore†, Clark DuMontier†, Cenk Yildirim, Jennifer La, Mara M. Epstein, David Cheng, Diana Cirstea, Sarvari Yellapragada, Gregory A. Abel, J. Michael Gaziano, Nhan Do, Mary Brophy, Dae H. Kim, Nikhil C. Munshi, Jane A. Driver† Equal first authorship

Journal of the National Cancer Institute113(8), 1084-1093
U.S. Veterans and VA Data Retrospective Cohort Study Multiple Myeloma Overall Survival Geriatric Oncology
2021

Contemporary Analysis of Electronic Frailty Measurement in Older Adults with Multiple Myeloma Treated in the National US Veterans Affairs Healthcare System.

Clark DuMontier†, Nathanael R. Fillmore†, Cenk Yildirim, David Cheng, Jennifer La, Ariela R. Orkaby, Brian Charest, Diana Cirstea, Sarvari Yellapragada, John Michael Gaziano, Nhan Do, Mary T. Brophy, Dae H. Kim, Nikhil C. Munshi, Jane A. Driver† Equal first authorship

Cancers13(12)
U.S. Veterans and VA Data Retrospective Cohort Study Electronic Health Records Multiple Myeloma Frailty