Abstract 14915: Role of Diabetes and Diabetic Medication in Cardiovascular Events and Survival Among Older Men With Prostate Cancer on Androgen Deprivation Therapy: Longitudinal SEER Medicare Analysis

Introduction: The effect of diabetes mellitus (DM) and DM therapy on cardiovascular events (CVE) in patients with prostate cancer (PC) undergoing androgen deprivation therapy (ADT) is unclear in the contemporary era.

Methods: Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database, we identified males ≥ 66-year-old with a new primary diagnosis of PC undergoing leuprolide therapy (ADT) between 2009-2017. These patients were followed for two years to identify a primary outcome of CVE that included heart failure (HF), atrial fibrillation (AF), acute myocardial infarction (AMI), peripheral artery disease (PAD), coronary artery disease (CAD), ischemic stroke (IS) and cardiovascular death. DM medications identified using part D data for this analysis were metformin, insulin, and other orals based on FDA approval dates until 2017. Adjusted Cox proportional hazards modeling was performed to estimate all-cause mortality in PC patients stratified by DM and among those with DM and on different therapies. Adjusted Fine-Gray modeling with appropriate competing risk (mortality or type of mortality) was utilized for other outcomes as presented. We adjusted for demographic factors, social determinants of health, cancer-specific factors, and other cardiovascular risk factors apart from the primary exposure of DM.

Results: This study included 9,072 PC patients. Among these 2,822 (31.1%) had DM, and 5,105 (56.3%) had cardiovascular disease prior to PC diagnosis. New CVE was diagnosed in 619 (6.8%; HF = 144, AF = 107, AMI = 40, PAD = 132, CAD = 226, IS = 66) patients in a 2-year period after the PC diagnosis. DM was noted to be a risk factor for CVE [adjusted subdistribution hazards ratio (aSHR) = 1.22 (95% CI= 1.07-1.44)]. The effect of DM and DM medication on mortality is presented in Table 1.

Conclusion: PC patients on ADT with DM have a higher risk of CVE and all-cause mortality. Metformin use is associated with reduced all-cause mortality.