[Lifetime risk of developing cancer in Inner Mongolia cancer registration areas]

Objective: Assess the cancer burden in Inner Mongolia to provide evidence for cancer prevention and control decision-making. Methods: Using cancer incidence and mortality data from 38 cancer registration areas in 2020, combined with demographic statistics and all-cause death data, the lifetime cancer risk in Inner Mongolia was calculated by the adjusted multiple primary cancer method. Results: The lifetime cancer risk in Inner Mongolia was 25.02% (95% CI: 24.99%-25.05%). The top five cancers with the highest lifetime risk were lung cancer (6.60%), colorectal cancer (3.12%), liver cancer (2.86%), gastric cancer (2.22%), and esophageal cancer (1.70%). Cancer risk remained low before age 40 years, while the remaining lifetime cancer risk decreased with increasing age. Males having significantly higher risk (26.92%, 95% CI: 26.88%-26.96%) than females (22.80%, 95% CI: 22.76%-22.84%).Urban residents had higher lifetime risk (26.56%, 95% CI: 26.52%-26.59%) than rural residents (23.62%, 95% CI: 23.58%-23.65%). Specifically, lung cancer and colorectal cancer risks were higher in urban areas, while esophageal cancer and liver cancer risks were higher in rural areas. The highest lifetime cancer risk was found among urban males at 28.26% (95% CI: 28.21%-28.32%), while the lowest cancer risk was observed among rural females at 21.18% (95% CI: 21.13%-21.23%). Conclusions: The lifetime risk of developing cancer in Inner Mongolia is 25.02%, with higher risk in males and urban areas. Future efforts should focus on population-specific screening optimization, achieve rational allocation of medical resources, improve multi-cancer surveillance and regional precision prevention, and provide scientific basis for comprehensive cancer control in Inner Mongolia.