The risk of fragility fractures in men with prostate cancer treated with androgen deprivation therapy.

Abstract

Androgen Deprivation Therapy (ADT) is known to increase long-term fracture risk in men with prostate cancer (PCa), although the risk of fragility fractures remains unclear. This study aims to evaluate the risk of fragility and malignancy-related fractures in men with PCa treated with ADT. We conducted a retrospective cohort study of men with PCa. Follow-up time was divided into 30-day intervals and exposure (current, past, or no-ADT use). Current ADT use was stratified by duration of ADT use (≤ 182days, 183-730days, and > 730days). Cause-specific Cox proportional hazard models were used to estimate the risk of fractures. We included 471 patients (mean age 70.5 (± 8.3) years). The mean follow-up time was 5.0 (± 1.7) years in patients who never started ADT, 3.4 (± 2.3) years and 4.1 (± 2.0) years in patients who started ADT at baseline and during follow-up, respectively. In total, 60 patients had a fracture, 48 (80%) fragility, and 12 (20%) malignancy-related fractures. Current ADT use was associated with a higher risk of all fractures (HR 5.10, 95% CI 2.34-11.13) and fragility fractures (HR 3.61, 95% CI 1.57-8.30). The association with malignancy-related fractures could not be studied due to no events during no-ADT use. There was an increased risk of all fractures with longer duration of ADT use. Current ADT use was associated with a higher risk of fragility fractures than no-ADT use. A higher fracture risk was observed within the first six months of ADT use and persisted for longer durations.