Risk of ischemic stroke in patients with prostate cancer receiving androgen deprivation therapy in Taiwan

Background Androgen deprivation therapy (ADT) in the treatment of prostate cancer may be associated with an increased risk of thromboembolic disease. The aim of our study was to investigate the association of ADT in the treatment of prostate cancer with ischemic stroke risk. Methods We identified individuals older than 20 years of age who were newly diagnosed with prostate cancer between January 1, 2005, and December 31, 2012. Patients who experienced ischemic stroke or transient ischemic stroke before the index date were excluded. Patients who received at least one prescription for ADT within 6 months were defined as the ADT user group. Patients who did not receive at least one prescription for ADT within 6 months were defined as the ADT nonuser group. The patients were followed until the first occurrence of one of the primary outcome measures (ischemic stroke or death) or until December 31, 2013. The primary composite outcome was the time to any cause of death or ischemic stroke. Results There was no significant difference in the primary composite outcomes in the prostate cancer patients between the ADT user and nonuser groups. Prostate cancer patients who received ADT had a higher mortality rate than those who were not treated with ADT, and the adjusted hazard ratio was 1.907 (95% confidence interval: 1.278–2.844; P = 0.0016) after adjusting for age, comorbidities and comedication use. Conclusion ADT in the treatment of prostate cancer may not be associated with an increased risk of ischemic stroke. The differences in thromboembolic effects in cardiovascular disease and ischemic stroke secondary to ADT should be further discussed and evaluated prospectively.