OBJECTIVES: To investigate the risk of thromboembolic disease (TED) in men with prostate cancer (PCa) on androgen deprivation therapy (ADT) while accounting for known TED risk factors.
MATERIALS AND METHODS: TED risk was assessed for 42,263 PCa men on ADT compared to a matched, PCa-free cohort of 190,930 men. Associations between ADT and deep venous thrombosis (DVT) or pulmonary embolism (PE) were analysed using multivariate Cox proportional hazard regression models. Previous PCa-related surgeries and the following proxies for disease progression: transurethral resection of the prostate, palliative radiotherapy and nephrostomy, were accounted for.
RESULTS: Between 1997-2013, 11,242 PCa men received anti-androgen (AA) monotherapy, 26,959 gonadotropin-releasing hormone (GnRH) agonists, 1,091 combined androgen blockade, and 3,789 underwent orchiectomy. When accounting for previous surgeries and proxies of disease progression, GnRH agonist users and surgically castrated men were at increased TED risk versus the comparison cohort, HR: 1.67 (95% CI: 1.40-1.98) and 1.61 (95% CI: 1.15-2.28), respectively. Men on AA monotherapy were at decreased risk, HR for DVT: 0.49 (95% CI: 0.33-0.74). TED risk was highest among those who switched from AA to GnRH agonists, PE HR: 2.55 (95% CI: 1.76-3.70). This increased from 2.52 (95% CI: 1.54-4.12) in year one, to 4.05 (95% CI: 2.51-6.55) in year two.
CONCLUSION: TED incidence among men on ADT increased with the duration of therapy and risk was highest for those who switched regimen, thus implicating roles for disease progression as well as ADT in propagating TED risk. Nonetheless, these findings support that only men with a relevant indication should receive systemic ADT.
2016. Vol. 118, no 3, 391-398 p.
prostate cancer, thromboembolic disease, disease severity, androgen deprivation therapy