Stroke and thromboembolic events in men with prostate cancer treated with definitive radiation therapy with or without androgen deprivation therapy.

BACKGROUND

There is conflicting evidence regarding the association between androgen deprivation therapy (ADT) for prostate cancer (PC) and the risk of developing stroke and thromboembolic events. Our study evaluated the association between ADT use and development of stroke, transient ischemic attack (TIA), deep vein thrombosis (DVT), and pulmonary embolism (PE) in a homogenous group of men with PC treated with definitive radiation therapy (RT) after controlling for multiple sources of confounding.

METHODS

Observational cohort study of patients diagnosed with PC at the US Department of Veterans Affairs between 1 January 2001 and October 31, 2015 and treated with definitive RT. Exposure was initiation of ADT within 1 year of PC diagnosis. Primary outcomes were development of stroke, TIA, DVT, or PE.

RESULTS

44,246 men with median follow-up of 6.8 years. The overall cumulative incidences of stroke, TIA, DVT, and PE at 10 years were 6.0, 3.0, 3.4, and 1.9%, respectively. In the multivariable competing risks model, there was a significant association between ADT and stroke (subdistribution hazard ratio (SHR) = 1.19, 95% CI = 1.09-1.30, p < 0.01), TIA (SHR = 1.24, 95% CI = 1.08-1.41, p < 0.01), and DVT (SHR = 1.18, 95% CI = 1.04-1.34, p < 0.01). ADT was only associated with PE in men receiving ADT for > 1 year (SHR = 1.34, 95% CI = 1.06-1.69, p-value = 0.03).

CONCLUSION

We observed an increase in the risk of stroke, TIA, and DVT in men receiving ADT and an increased risk of PE in men receiving long-term ADT. These results highlight concerns regarding long-term risks of ADT on stroke and thromboembolic events in the treatment of PC.