Abstract PR013: Glycemic control and risk of prostate cancer morality in Veterans with diabetes

Abstract Background Unlike many other cancers, there is an inverse association between prostate cancer risk and type 2 diabetes mellitus (T2DM) diagnosis. There is also evidence of existing racial disparities in prostate cancer incidence and mortality among those with T2DM diagnosis. The reasons for racial inequity are multifactorial. In this retrospective cohort study, we estimated the association between glycemic control (HbA1c) in US Veterans with diagnosed diabetes and determined risk of prostate-cancer specific mortality. Methods A retrospective, longitudinal cohort study of national clinical and administrative data in male Veterans over the age of 45 with T2DM without a cancer diagnosis was collected from the VA’s Corporate Data Warehouse (CDW). Baseline social, demographic, and health-related factors were reported by race ethnicity and assessment of any differences in these variables were made using appropriate statistical tests. Competing risk Cox regression model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for glycemic control and prostate cancer mortality. Results A total of 763,424 Veterans with diabetes without cancer diagnosis at baseline were included. Among these Veterans, those with moderate glycemic control (HbA1c 7-8%) were associated with a 23% (HR= 0.77; 95% CI: 0.69, 0.86) lower risk of prostate cancer mortality compared to men with good glycemic control (HbA1c <7%) when adjusting for social, demographic and clinical factors (p< 0.001). Likewise, those with poor glycemic control (HbA1c >8%) were associated with 15% (HR=0.85; 95% CI: 0.73, 1.00) lower risk of prostate cancer mortality compared to those with HbA1c <7%. A similar lower risk of prostate cancer mortality was observed when considering the non-Hispanic white (NHW) population with moderate glycemic control (HR=0.82; 95% CI: 0.72-0.94). The non-Hispanic black (NHB) population also demonstrated lower risk of mortality with moderate glycemic control (HR=0.58; 95% CI:0.45-0.76). However, there was no significant association between risk of prostate cancer mortality and the higher glycemic control (A1c >8%) for both NHW (HR=0.88; 95% CI: 0.73, 1.07) and NHB (HR=0.75; 95% CI: 0.53, 1.06). Conclusion In this large, retrospective study of male Veterans with T2DM, we observed an inverse association between glycemic control and prostate cancer mortality. However, even in an equal-access healthcare setting like the VA, reasons for differences in mortality risk among NHW and NHB Veterans is unclear. Further research is required to identify these factors, which would ultimately improve racial inequalities in prostate cancer and diabetes care. Citation Format: Michael Marrone, Kinfe Bishu, Macelyn Batten, Mulugeta Gebregziabher. Glycemic control and risk of prostate cancer morality in Veterans with diabetes [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr PR013.