Risk of fracture after androgen deprivation for prostate cancer

Background: The use of androgen-deprivation therapy for prostate cancer has increased substantially over the past 15 years. This treatment is associated with a loss of bone-mineral density, but the risk of fracture after androgen-deprivation therapy has not been well studied. Methods: We studied the records of 50,613 men who were listed in the linked database of the Surveillance, Epidemiology, and End Results program and Medicare as having received a diagnosis of prostate cancer in the period from 1992 through 1997. The primary outcomes were the occurrence of any fracture and the occurrence of a fracture resulting in hospitalization. Cox proportional-hazards analyses were adjusted for characteristics of the patients and the cancer, other cancer treatment received, and the occurrence of a fracture or the diagnosis of osteoporosis during the 12 months preceding the diagnosis of cancer. Results: Of men surviving at least five years after diagnosis, 19.4 percent of those who received androgen-deprivation therapy had a fracture, as compared with 12.6 percent of those not receiving androgen-deprivation therapy (P<0.001). In the Cox proportional-hazards analyses, adjusted for characteristics of the patient and the tumor, there was a statistically significant relation between the number of doses of gonadotropin-releasing hormone received during the 12 months after diagnosis and the subsequent risk of fracture. Conclusions: Androgen-deprivation therapy for prostate cancer increases the risk of fracture.