OBJECTIVES: Androgen deprivation therapy (ADT) is a staple of advanced prostate cancer (PCa) treatment, however several side-effects are associated with its long-term use. Notably, loss of bone mineral density (BMD) is accelerated which increases fracture risk. Although guidelines recommend BMD testing when initiating ADT to properly assess baseline fracture risk, there is scarce data to support this recommendation in the PCa patient population. The objective was to examine the association between baseline BMD testing (bBMDT) and the risk of fractures in men initiating ADT for PCa.

METHODS: The cohort consists of men extracted from Quebec public healthcare insurance administrative databases who were diagnosed with PCa from 2004-2015 and treated by ADT. Only patients who received at least one year of continuous ADT treatment were included. bBMDT was defined as a BMD test performed from 12 months prior to ADT initiation and up to 3 months after. The primary study outcomes were incidence of any fracture and incidence of fractures resulting in hospitalization. Adjustment for confounders was performed with inverse probability of treatment weights (IPTW) and included baseline characteristics such as patient demographic variables, comorbidities, risk factors for fractures.

RESULTS: We identified 13,352 patients during the study period, of which 2,070 (15.3%) underwent bBMDT. In adjusted analyses, bBMDT (hazard ratio [HR] 0.92, 95% confidence interval [CI] 0.76-1.12) was not associated with the risk of fracture. For fractures requiring hospitalization, bBMDT was associated with a lower risk (HR 0.72, 95%CI 0.52-0.98), with an IPTW-adjusted 5-year incidence 6.8% for patients not receiving bBMDT and 4.7% for patients receiving bBMDT.

CONCLUSIONS: In our study population, bBMDT was associated with a lower risk of fractures resulting in hospitalization. Given the low uptake of bBMDT, additional efforts emphasizing the importance of BMD testing in guidelines may be needed.