Bayesian model prediction of colorectal cancer incidence in Jiangsu Province, China, a cancer registry-based study

The most recent colorectal cancer incidence trends in Jiangsu Province, China, have not been reported; this study aims to provide a comprehensive analysis of present local incidence patterns and future trends projected through 2035. Annual data on colorectal cancer cases ‌from‌ 16 cancer registries in Jiangsu Province were analyzed ‌to assess‌ temporal trends from 2009 to 2021. Trends in previous incidence rates of colorectal cancer were analyzed using the Joinpoint regression model, and future incidence rates from 2022 to 2035 were projected using the Bayesian age-period-cohort model. Both crude and age-standardized incidence rates of colorectal cancer presented significant upward trends from 2009 to 2021, with average annual percentage changes of 6.16% (95% CI: 5.72–6.63%) and 3.55% (95% CI: 2.86–4.25%), respectively; these rates were highest in urban males and increased fastest in rural males. APC model analysis revealed a pronounced age effect and modest cohort effect for incidence growth. By 2035, overall crude and age-standardized incidence rates were projected to reach 87.69 per 100,000 and 29.20 per 100,000, respectively, with males contributing most significantly to the overall increase. Without enhanced interventions, the crude incidence rate of CRC in 2035 is projected to reach 2.25 times the 2021 baseline. Screening strategies involving fecal immunochemical test and colonoscopy should be prioritized to reduce population-level incidence rates, particularly among males and those older than 50.