Predictions of colorectal cancer incidence trend in Jiangsu Province, China: a Bayesian modelling study

Abstract Background: The most recent colorectal cancer incidence trends in Jiangsu Province, China, remain not reported, this study aims to provide a comprehensive analysis of present local incidence patterns and future trends projected through 2035. Methods: Annual ‌information‌ of colorectal cancer cases ‌from‌ 16 cancer registries in Jiangsu Province was analyzed ‌to assess‌ temporal trends from 2009 to 2021. The future ‌burden‌ of colorectal cancer ‌incidence‌ from 2022 to 2035 was projected ‌using‌ the Bayesian age-period-cohort model. Results: Both crude and age-standardized incidence rates of colorectal cancer presented significant upward trends from 2009 to 2021, with average annual percentage changes of 6.20% (95% CI: 5.70-6.60%) and 3.60% (3.00-4.10%), respectively; these rates were highest in urban males but increased fastest in rural males. APC model analysis revealed a pronounced age effect and modest cohort effect; by 2035, overall crude and age-standardized incidence rates were projected to reach 63.00 per 100,000 and 28.76 per 100,000, respectively, with urban males contributing most significantly to the overall increase. Conclusions: Without enhanced interventions, new cases in 2035 are projected to reach 1.6 times the 2021 baseline. Screening strategies involving FIT and colonoscopy must be urgently implemented to reduce population-level incidence rates, particularly among urban males over 45.