A population-based study of cardiovascular (CV) mortality among patients with prostate cancer (PCa) treated with radical external beam radiation therapy (EBRT) with and without adjuvant androgen deprivation therapy (ADT) at a provincial cancer agency.

Abstract

4656 Background: There are conflicting studies of the impact of ADT on CV mortality among PCa patients receiving curative intent EBRT. D’Amico et al suggested that men > 65 yrs are at increased risk of CV mortality with ADT. We assessed the impact of ADT on CV mortality in patients treated in British Columbia. Methods: Provincial pharmacy and radiotherapy databases were linked to the provincial cancer registry, and defined a cohort of patients treated with curative intent EBRT between 1998 and 2005. We determined the duration of ADT, and the cumulative incidence of CV death. We compared death from CV disease with and without ADT, and by duration of ADT using competing risk analysis and Fine and Gray multivariant analysis. 600 randomly selected patients were reviewed to determine baseline CV disease, CV risk factors, and Charlson Index. Results: We identified 5,948 PCa patients treated with radical intent EBRT, of which 1,933 were treated without ADT, 674 received ADT for ≤6 mo and 3,341 received > 6 mo of ADT. The cumulative CV mortality at 7 yrs was 2.6% [95%CI 1.9 to 3.5%], 2.1% [1.2 to 3.5%], and 1.4 [1.0 to 2.0%] for patients with no ADT, ≤ 6 mo NADT and > 6 mo ADT respectively (Gray's p=0.002). Baseline CVS disease and risk factors were more prevalent in the no ADT group compared to the > 6 month ADT group. Conclusions: This study demonstrated a lower CV mortality rate among patients treated with longer durations of ADT than those treated without ADT. These differences likely relate to selection of patients for ADT, rather than effect of ADT itself. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration AstraZeneca, Ferring Pharma, sanofi-aventis AstraZeneca, Ferring Pharma, sanofi-aventis Abbott Laboratories