Abstract
BACKGROUND: Among the approved therapies for metastatic hormone-sensitive prostate cancer (mHSPC), abiraterone and docetaxel are administered concomitantly with corticosteroids. This study evaluated the association between corticosteroid use and risk of adverse events among patients with mHSPC. METHODS: We conducted an observational cohort study among patients ≥ 65 years of age who were enrolled in Medicare parts A, B, or D, and initiated treatment for mHSPC. The primary exposure was corticosteroids between June 1, 2017-December 31, 2023. Primary outcomes were nine composite adverse event outcomes. Exploratory outcomes were all-cause death, all-cause hospitalization, and adverse event-related hospitalization. Conventional Cox models were used to model corticosteroid exposure as a binary time-varying covariate, and weighted cumulative exposure models were used to account for varying doses, durations, and timing of corticosteroid exposure. RESULTS: Of 24,857 patients, 12,839 (52%) received at least one dose of corticosteroids during the follow-up period. Compared with patients who were not exposed to at least one ≥ 5 mg prednisone-equivalent dose of corticosteroids, patients exposed to corticosteroids during follow-up were at significantly higher risk of all adverse event types, except ophthalmic events, and had a 34% higher risk of all-cause death (adjusted hazard ratio: 1.34; 95% confidence interval: 1.27-1.42). Risks increased with prolonged corticosteroid exposure and with higher daily doses. CONCLUSIONS: Our findings suggest that patients exposed to corticosteroids are at increased risk of adverse events, hospitalization, and death. As not all mHSPC treatments require concomitant use of corticosteroids, these findings may help to inform treatment decision-making.