Temporal Trends, Projections, and Risk Attribution of Colorectal Cancer in Australia, China, Japan, and Korea: GBD 2021 Analysis (1990–2041)

Purpose To generate implementation-ready evidence on colorectal cancer (CRC) burden and prevention priorities across four Asia–Pacific countries. Patients and Methods We analyzed Global Burden of Disease 2021 (GBD 2021) estimates for Australia, China, Japan, and the Republic of Korea (Korea) for 1990–2021. Outcomes included prevalence, incidence, mortality, and disability-adjusted life years (DALYs) as counts and age-standardized rates (ASRs) with 95% uncertainty intervals (UIs). For clarity, ASR components were the age-standardized prevalence rate (ASPR), age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and age-standardized disability-adjusted life-year rate (ASDR). Temporal trends used log-linear models to derive average annual percent change (AAPC) and Joinpoint regression; future trajectories (2022–2041) applied autoregressive integrated moving average (ARIMA) models. We performed Das Gupta decomposition (population growth, population aging, and epidemiologic change), assessed correlations with the Socio-demographic Index (SDI), and summarized sex-stratified population-attributable fractions (PAFs) for six modifiable risks (dietary risks, high body mass index (BMI), high fasting plasma glucose, low physical activity, alcohol use, and tobacco use). Results China had the largest counts in 2021; Japan had the highest ASPR. Men bore higher incidence, mortality, and DALY rates, with widening male disadvantages in China and Korea. From 1990–2021, ASPR/ASIR rose in China and Korea, while Australia’s ASPR was stable and ASIR declined; ASMR/ASDR fell in all countries, greatest in Australia. Decomposition attributed rising counts primarily to aging (notably China/Japan) with epidemiologic change contributing in China/Korea. SDI correlated inversely with ASMR/ASDR. Dietary risks were the leading contributors to deaths and DALYs, followed by high BMI and high fasting plasma glucose; PAFs were consistently higher in men. Forecasts suggest continued increases in prevalence/incidence in China/Korea, sustained declines in severity endpoints in Australia, and stability or gradual improvement in Japan through 2041. Conclusion Priorities include scaling high-quality screening and integrated risk-factor control—especially for men—in China and Korea, and sustaining early detection and survivorship gains in Japan and Australia. Findings support resource-appropriate implementation strategies in diverse health-system contexts.