Next-generation sequencing utilization among U.S. Veterans with metastatic cancer in the VA Healthcare System

Background: Access to molecular and genetic testing enables the delivery of precision oncology and improved cancer outcomes. However, patterns of testing utilization among U.S. Veterans remain understudied. This study evaluated the receipt of FoundationOne next-generation sequencing (NGS) testing for metastatic patients across three common cancers. We assessed demographic, clinical, and social determinants of health (SDOH) correlates of testing within the nationwide Veterans Affairs (VA) healthcare system. Methods: We conducted a retrospective cohort study of U.S. Veterans recorded in the VA Cancer Registry with metastatic lung, colorectal, or prostate cancer and treated in the VA system from 2019 - 2023. We evaluated the utilization of FoundationOne NGS panels (CDx and Liquid) by year and cancer type as accessed through the National Precision Oncology Program (NPOP) database; for this study period other NGS platforms were beyond the scope of this study. Associations of testing frequency with SDOH, including self-reported race, ethnicity, age, sex, rurality, and socioeconomic status, were examined using descriptive statistics, with standard mean differences (SMD) >0.1 considered significant. Results: Among 71,569 cancer patients, 17.4% (n = 12,465) had metastatic disease. Of these, 4,743 patients received FoundationOne NGS testing (38.1%) including 514 colorectal cancer patients, 2,519 lung cancer patients across histologies, and 1,710 prostate cancer patients. Tested patients were younger than non-tested patients (median age of 71.5 vs. 72.8, SMD = 0.26). Differences in racial distribution were observed (SMD = 0.14); for example, 27.7% of tested patients were Black or African American compared to 22.4% of non-tested patients. Tested patients were more likely to be non-frail (36.6% vs. 31.8%) and less likely to be severely frail (4.2% vs. 6.0%, SMD = 0.15) than non-tested patients, while no substantial disparities were found across sex (SMD = 0.053) or ethnicity (SMD = 0.04). The proportion of rural patients was lower for tested colorectal (20.2% vs. 24.7%, SMD = 0.11) and lung cancer patients (29.3 % vs. 34.3%, SMD = 0.12) versus non-tested patients; tested patients also resided closer to VA facilities for colorectal (median of 24.6 km vs. 31.9 km, SMD = 0.13) and prostate cancer (25.6 km vs. 32.1 km, SMD = 0.11). Conclusion: Among Veterans with common metastatic cancers, we identified differences in FoundationOne NGS testing utilization for some demographic and clinical factors, while other factors showed similar testing rates. Future directions include evaluating additional NGS platforms utilized in the VA, as well as NGS testing through community care. Continued investment in interventions such as tele-oncology and targeted outreach may help increase NGS testing and ensure all Veterans benefit from precision cancer care.