Androgen deprivation and thromboembolic events in men with prostate cancer

BACKGROUND: Androgen deprivation therapy (ADT) improves prostate cancer outcomes in specific clinical settings, but is associated with adverse effects, including cardiac complications and possibly thromboembolic complications. The objective of this study was to estimate the impact of ADT on thromboembolic events (TEs) in a population-based cohort. METHODS: In the linked Surveillance, Epidemiology and End ResultsMedicare database, we identified men older than 65 who were diagnosed with nonmetastatic prostate cancer between 1999 and 2005. Medical or surgical ADT was identified by Medicare claims for gonadotropin-releasing hormone agonists or bilateral orchiectomy at any time following diagnosis. TEs included deep venous thrombosis, pulmonary embolism, and arterial embolism. The impact of ADT on the risk of any TE and on total number of events was estimated, controlling for patient and tumor characteristics. RESULTS: Of 154,611 patients with prostate cancer, 58,466 (38%) received ADT. During a median follow-up of 52 months, 15,950 men had at least 1 TE, including 8829 (55%) who had ADT and 7121 (45%) with no ADT. ADT was associated with increased risk of a TE (adjusted hazard ratio = 1.56; 95% confidence interval, 1.50-1.61; P < .0001), and duration of ADT was associated with the total number of events (P < .0001). CONCLUSIONS: In this population-based cohort, ADT was associated with increased risk of a TE, and longer durations of ADT were associated with more TEs. Men with intermediate- and low-risk prostate cancer should be assessed for TE risk factors before starting ADT and counseled regarding the risks and benefits of this therapy. Cancer 2011. (c) 2011 American Cancer Society.