Global Trends in Prostate Cancer Incidence Among Men Aged 55+ (1992-2021): An Age-Period-Cohort Analysis

With global population aging, lifestyle transitions, and the widespread expansion of screening practices, the burden of prostate cancer has shown complex geographical variations. The study aims to dissect the age, period, and cohort effects on prostate cancer incidence dynamics using the Age-Period-Cohort (APC) model, and to infer potential drivers behind these effects so as to provide evidence for effective prevention and control strategies.

Using data from the Global Burden of Disease (GBD) 2021, we analyzed trends in prostate cancer incidence among men aged 55 years and older from 1992 to 2021 across the globe, five sociodemographic index (SDI) regions, and 204 countries. An age-period-cohort model was applied to estimate net drifts, local drifts, longitudinal age curves, and period and cohort relative risks.

In 2021, approximately 1.26 million new cases of prostate cancer were reported in men aged 55 and older, accounting for 96% of global new cases. This represented a 135.86% increase in new cases compared to 1992. The global age-standardized incidence rate (ASIR) for this group was 180.94 per 100,000 (95% UI: 166.43-191.24). The APC model indicated a net drift of -0.36% (95% confidence interval [CI]: -0.57 to -0.15). A significant correlation was found between prostate cancer ASIR and SDI (r = 0.54, p < 0.001), with the highest rates observed in high SDI regions (416.24 per 100,000) and the lowest in low-middle SDI regions (78.18 per 100,000). Notably, low-middle SDI regions experienced the fastest increase in ASIR, with a net drift of 1.50% (95% CI: 1.15-1.86). This study revealed three distinct age-stratified incidence patterns across SDI regions. Meanwhile, APC analysis showed that incidence increased with age in all SDI regions. High SDI regions exhibited favorable period and cohort effects, while low-middle SDI regions showed unfavorable trends in both period and cohort relative risks. At the country level, the United States and China had the highest case numbers, while countries like Georgia and Russia showed the fastest increase. Canada and Australia demonstrated a downward trend.

Substantial health inequalities in prostate cancer screening, diagnosis, and treatment persist across SDI levels, with the future global burden expected to rise disproportionately in low-middle SDI regions. These disparities underscore the need for context-specific prevention and control strategies to promote global equity in prostate cancer management.