Fracture risk in androgen deprivation therapy: a Canadian population based analysis

Prostate cancer is the most common noncutaneous malignancy diagnosed in men. The use of androgen deprivation therapy (ADT) is the mainstay of treatment for metastatic disease. The use of ADT has been reported to increase the risk of osteoporosis in men with prostate cancer, with higher risk of fracture than age matched controls. We sought to confirm the higher fracture risk of men with prostate cancer on ADT in the Canadian population.

We used the Population Health Research Data Repository housed at Manitoba Centre for Health Policy to identify all cases of fractures of the hip, vertebra, or wrist in men aged 50 years and older occurring between 1996 and 2004. Each case was matched with up to three controls by age, sex, ethnicity and medical comorbidity. We calculated the odds ratios (OR) for fracture with prostate cancer, and with or without ADT, after adjusting for possible confounding variables.

There were 4696 cases of fracture matched with 14080 controls. After controlling for confounding variables, there was no significant association between prostate cancer and fracture risk (adjusted OR = 0.97, 95% confidence intervals [CI]: 0.83-1.15). We detected a significant association between ADT and fracture risk in men. The adjusted ORs for current and past ADT usage were 1.71 (95% CI: 1.13 - 2.58) and 2.42 (95% CI: 1.42-4.12) respectively.

Our findings suggest that prostate cancer itself does not increase the risk of fracture and corroborate published results demonstrating an association between ADT and fractures.