Androgen deprivation therapy (ADT) or orchiectomy is associated with an increased risk of osteoporosis or fracture. In this nationwide database analysis, we found that ADT or orchiectomy increased the risk of fracture in Chinese patients with prostate cancer. However, the magnitude of increase is seemingly not as large as that in Western populations.
Introduction: ADT using gonadotropin-releasing hormone (GnRH) agonists or orchiectomy is associated with an increased risk of osteoporosis or fracture. To investigate the effects of ADT duration or orchiectomy on any type of fracture in Asian patients with prostate cancer, we conducted this retrospective analysis using a nationwide database in Taiwan.
Methods: We included 17,359 subjects who were newly diagnosed with prostate cancer between January 1, 1998, and December 31, 2007. The risk of first fracture was our primary endpoint.
Results: The rates of fracture from 12 months after prostate cancer diagnosis until the last follow-up date were 8.7 % for all patients, 7.1 % for patients who did not receive ADT or orchiectomy, 9.8 % for patients who received ADT, and 14.4 % for patients who received orchiectomy with or without ADT (P < 0.0001). In a Cox proportional hazard analysis, the relative risk of fracture increased steadily with the number of doses of GnRH agonists received during the first year after cancer diagnosis and with dose density. A significant hazard ratio was observed in patients who received at least nine doses within 1 year after diagnosis and in those whose dose density exceeded two doses per year. Age greater than or equal to 65 years was associated with a significantly lower risk of fracture.
Conclusion: ADT or orchiectomy increases the risk of fracture in Chinese patients with prostate cancer. However, the magnitude of this increase is seemingly not as large as that in Western populations.