Increased Risk of Pneumonia in Patients Receiving Gonadotropin-Releasing Hormone Agonists for Prostate Cancer

BACKGROUND This study aimed to investigate the relationship between the use of gonadotropin-releasing hormone (GnRH) agonists and subsequent risk of pneumonia in patients with prostate cancer (PC) using a population-based dataset. METHODS We obtained the data from Taiwan's Longitudinal Health Insurance Database 2000. We included 2064 PC in this study. Of the sampled PC patients, 1207 received treatment with GnRH agonists. We individually traced each PC patient for a 1-year period to identify those who were hospitalized with pneumonia. We performed a Cox proportional hazard regression to explore the association between the use of GnRH agonists and the risk of pneumonia during the 1-year follow-up period. RESULTS Incidence rates of pneumonia during the 1-year follow-up period were 4.35 (95% confidence interval (CI): 1.89∼9.64) per 100 person-years and 2.14 (95% CI: 1.31∼3.32) per 100 person-years for PC patients who did and those who did not receive treatment with GnRH agonists, respectively. The log-rank test suggested that there was a significant difference in the 1-year pneumonia-free survival rate between PC patients who did and those who did not receive treatment with GnRH agonists (p<0.002). After adjusting for age, monthly income, and the Charlson Comorbidities Index score, PC patients who received treatment with GnRH agonists were more likely to have been hospitalized for pneumonia during the 1-year follow-up period than PC patients who did not receive treatment with GnRH agonists (hazard ratio: 1.92, 95% CI: 1.10∼3.36). CONCLUSIONS PC patients who received treatment with GnRH agonists had an increased risk of pneumonia.