Abstract 2359: Validation of prostate cancer diagnosis and cause of death in a national cohort of male veterans with type 2 diabetes mellitus.

Abstract Background: Accurate diagnosis and determination of cause of death are essential for effective disease surveillance, health planning, and research. This study seeks to validate the diagnostic accuracy and cause of death data related to prostate cancer (PCa) among Veterans with type 2 diabetes mellitus (T2DM). Methods: We conducted a retrospective cohort study of Veterans with type 2 diabetes (T2DM) diagnosed between 2010 and 2019, using data from the Veterans Health Administration (VHA) Corporate Data Warehouse (CDW). Diagnostic codes and cause of death information were obtained from the Prostate Cancer Data Core (PCDC) and the National Death Index (NDI), which served as the gold standard for validating CDW data. Concordance between data sources was evaluated using Cohen’s Kappa statistic, along with measures of diagnostic performance such as sensitivity and specificity. Result: Among 763,424 Veterans with T2DM, 37,048 were diagnosed with PCa in the CDW and 36,861 in the PCDC, with concordance rate of 98.7%. Mortality data from the NDI revealed 2,723 deaths with PCa as the underlying cause, of whom 75.4% had a recorded diagnosis of PCa in CDW. For all-cause mortality, 328,156 Veterans were identified as deceased in the CDW Vital Status File (VSF) and 326,707 were reported as deceased in the NDI, with a concordance rate of 99.3% deaths between the two sources. Comparing incident PCa diagnoses for all patients, we found that the CDW had a high sensitivity 98.6% and specificity 99.9%. Similarly, for cause specific death, the sensitivity rate was 75.5% and specificity was 100.0%. Conclusions: The findings demonstrate a high level of concordance in key outcomes of interest, specifically, prostate cancer (PCa) diagnosis between the CDW and PCDC, and all-cause mortality between CDW VSF and NDI data sources. Given the time-consuming nature of data retrieval and management from the CDW, we recommend using the PCDC for PCa diagnosis and CDW VSF for all-cause mortality ascertainment. Citation Format: Mulugeta Gebregziabher, Kinfe G. Bishu, Andrew Schreiner, . Validation of prostate cancer diagnosis and cause of death in a national cohort of male veterans with type 2 diabetes mellitus [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 2359.