PCN229 POPULATION BASED ANALYSIS OF RATES OF USE OF NOVEL HORMONAL AGENTS AT THE END-OF-LIFE IN MEN WITH CASTRATION-RESISTANT PROSTATE CANCER

The approval of novel hormonal agents (NHAs), abiraterone and enzalutamide, have increased the therapeutic arsenal available in metastatic castration-resistant prostate cancer (mCRPC). However, the use of chemotherapy and other antineoplastics at the end-of-life has been suggested as an indicator of aggressive quality of care. In this study, we report the use of NHAs at the end-of-life in men with mCRPC in the province of Quebec, Canada. Using Quebec healthcare administrative databases, we identified patients with prostate cancer who used an NHA (abiraterone or enzalutamide) and who died between 2012 and 2016. The primary outcome was the use of an NHA in the 30 days before death. Use of an NHA in the 60 and 90 days before dying, and initiation of an NHA in the 30 days before death were evaluated as secondary outcomes. Multivariable analysis of the primary outcome was performed with logistic regression with results reported as odds ratios (OR) with 95% confidence intervals (95%CI). The cohort consists of 1316 patients who used an NHA over the course of their disease, with 292 (22.2%), 464 (35.3%), and 575 (43.7%) having used an NHA in the 30, 60 and 90 days of life, respectively. Use of NHA 30 days before dying decreased from 44.8% in 2012 to 17.0% in 2016 (Cochran-Armitage test p-value<0.001). On multivariable analyses, later years of death remained associated with lower odds of NHA use 30 days before death (OR 0.74, 95%CI 0.66 to 0.81, p<0.001). Fifty-eight (4.4%) patients initiated a NHA 30 days before dying. Rates of NHA use 30 days before dying were high initially but decreased over the study period. Further assessment of NHA use at the end of life is warranted to examine if the trend will be maintained given the recent approval of additional NHAs for prostate cancer.