Global trends in prostate cancer burden among adults aged 80 years and older from 1990 to 2021 based on the global burden of disease 2021.

OBJECTIVES: This study aimed to investigate the global, regional, and national burden of prostate cancer (PCa) among adults aged 80 years and older (≥ 80 years) from 1990 to 2021. METHODS: Using data from the Global Burden of Disease 2021 (GBD 2021) study, we systematically analyzed PCa incidence, mortality, and disability-adjusted life years (DALYs) among populations aged ≥ 80 years across 204 countries and territories. Patients were grouped by age (80-84, 85-89, 90-94, and ≥ 95 years), and burden was assessed by geographic region and socio-demographic index (SDI). Temporal trends were examined using Joinpoint regression to calculate the annual percentage change (APC) and average annual percentage change (AAPC), with 95% confidence intervals. Regional disparities were visualized using map-based analysis, and the contributions of risk factors were assessed. Bayesian age-period-cohort (BAPC) models projected future trends to 2040. RESULTS: From 1990 to 2021, the incidence rate of PCa in those aged ≥ 80 years showed an overall decline (AAPC = -0.43%, 95% CI -0.52 to -0.35), while the absolute number of incidence, deaths, and DALYs increased steadily across all age groups, potentially associated with population aging. Incidence and mortality rates peaked in the mid-1990s, then fell most rapidly between 2007 and 2013, especially in high- and high-middle SDI regions. In contrast, low- and low-middle SDI regions experienced slower declines or persistent increases. In 2021, the highest incidence and mortality rates occurred in select Caribbean nations, while the lowest rates were found in Central Asia. Smoking remained the leading modifiable risk factor, but its impact decreased in higher SDI regions. Dietary factors, especially milk and calcium intake, were protective. BAPC modeling suggests that the decline in incidence, mortality, and DALYs is likely to continue through 2040, although uncertainty in projections increases over time, especially in low-SDI regions. CONCLUSIONS: While substantial global progress has been made in reducing PCa incidence, mortality, and DALYs among adults aged ≥ 80 years, significant disparities persist, especially in low-resource settings, mainly due to differences in detection, treatment, and risk reduction strategies. Ongoing efforts to promote equitable access to early detection, effective treatment, and risk factor mitigation are essential to further reduce the burden of PCa in the aging population worldwide.