Increased risk of a herpes zoster attack in patients receiving androgen deprivation therapy for prostate cancer

This study aimed to examine the association of herpes zoster (HZ) with androgen deprivation therapy (ADT) use among patients with prostate cancer (PC), using a population-based data set. The study sample for this study was retrieved from the Taiwan Longitudinal Health Insurance Database 2005. We selected 877 patients with PC who had received ADT as the study group, while 849 patients with PC who had not received ADT served as the comparison group. Each study patient was individually tracked for a 3-year period to discriminate those who subsequently received a diagnosis of HZ. Of the total 1,726 sampled patients, the incidence rate of HZ per 100 person-years was 1.80 (95% CI: 1.41–2.25) during the 3-year follow-up period. In particular, incidence rates of HZ per 100 person-years were 2.36 (95% CI: 1.75–3.13) and 1.24 (95% CI: 0.81–1.81), respectively, for patients with PC who had and those who had not received ADT. Furthermore, Cox proportional hazard regressions showed that the adjusted hazard ratio for an HZ attack during the 3-year follow-up period for patients with PC who had received ADT was 1.88 (95% CI: 1.13–3.11) than those who had not received ADT. We concluded that patients with PC who had received ADT had an increased risk of HZ.