Differences in prostate tumor characteristics and survival among religious groups in Songkhla, Thailand

Abstract

Background: The incidence and mortality from prostate cancer is expected to increase in the next decade in Thailand. Despite the perceived lower risk in this population vs. developed, western countries, it is becoming an important public health issue. Prostate cancer incidence varies between the most predominant religious groups in Thailand, Buddhists and Muslims. However limited data is available describing the prostate cancer survival in these two populations. Here we examine differences in prostate tumor characteristics and survival between Buddhists and Muslims in the province of Songkhla, Thailand. Methods: 945 incident prostate cancer cases (1990-2014) from the population-based Songkhla Cancer Registry were used in this analysis. Age, grade, stage, and year at diagnosis were compared across religious groups, using Wilcoxon or Chi-square tests. Kaplan Meier methods were used to estimate the median survival time and 5-year survival probabilities. Cox proportional hazards models were used to estimate hazard ratios (HR) between religious groups and 95% confidence intervals (CI) for mortality in age-adjusted and fully-adjusted models. Results: Prostate tumor characteristics, age, and year at diagnosis were similar across religious groups. The median survival time after diagnosis of prostate cancer was longer in Buddhists 3.8 years compared with Muslims 3.2 years (p = 0.08). The age-adjusted risk of death after prostate cancer diagnosis was higher in Muslims compared with Buddhists (HR: 1.31; 95%CI: 1.00, 1.72). After adjustment by stage and grade, results were slightly attenuated (HR: 1.27, 95%CI: 0.97, 1.67). Conclusion: Muslims have shorter survival after prostate cancer diagnosis than do Buddhists in Thailand. The reasons underlying this difference require additional investigation in order to design targeted interventions for both populations.