Risk of age-related macular degeneration in patients with prostate cancer: a nationwide, population-based cohort study

Abstract

Background: Prostate cancer (PC) can be related to increased systemic oxidative stress and dihydrotestosterone level, which are also reported to be involved in the pathogenesis of age-related macular degeneration (AMD). We conducted a cohort study to determine whether patients with PC have an increased risk of AMD.

Patients and methods: Data were collected from the Taiwan Longitudinal Health Insurance Database for the 1999-2010 period. The study PC cohort comprised 22 084 patients aged ≥18 years with a first diagnosis of PC. The comparison cohort consisted of age-, occupation-, and urbanization level-matched patients at a ratio of 1 : 1. The primary outcome was the incidence of AMD, which was evaluated using Kaplan-Meier survival analysis and proportional hazards modeling.

Results: The mean follow-up periods (standard deviation) for the patients with AMD in the age-, occupation-, and urbanization level-matched PC cohort and non-PC cohorts were 4.69 (2.90) and 5.51 (2.82) years. The mean age of the PC cohort was 73.9 years and that of the non-PC cohort was 73.2 years, with approximately 85.9% of the patients aged >65 years. The PC cohort had a higher risk of AMD than did the propensity score-matched non-PC cohort with an adjusted hazard ratio of 1.25 (95% confidence interval, 1.12-1.39). Compared with PC cohort receiving no injection hormone therapy, the PC cohort receiving injection hormone therapy had a lower risk of AMD (adjusted hazard ratio, 0.56; 95% confidence interval, 0.41-0.76).

Conclusion: PC is associated with an increased risk of AMD. Patients with PC receiving injected form of androgen deprivation therapy had a lower risk of AMD than patients with PC not receiving injected form of androgen-deprivation therapy.

Keywords: age-related macular degeneration; cohort study; prostate cancer.