Abstract: Background and purpose: This study aimed to estimate the incidence and mortality rates of colorectal cancer in China, in 2015, based on population-based cancer registration data collected by the National Cancer Center. Methods: Based on the data quality review and assessment, the cancer registration data from 501 cancer registries in China were included in this study, which included new cases and deaths during 2015. According to the national population data in 2015, the nationwide incidence and mortality of colorectal cancer were estimated. Results: The data from 368 cancer registries were qualified, which covered a total of nearly million populations in China, accounting for 22.52% of the national population. There were 387.6 thousand new colorectal cancer cases (225.0 thousand males and 162.6 thousand females) estimated in China in 2015. The age-standardized incidence rate by Chinese standard population (ASRC) was 18.02 per 100 000 (male: 21.36 per 100 000; female: 14.79 per 100 000). The age-standardized incidence rate by World Segi′s population (ASRW) was 17.81 per 100 000 (male: 21.21 per 100 000; female: 14.54 per 100 000). There were 187.1 thousand colorectal cancer deaths (109.5 thousand males and 77.6 thousand females) estimated in China in 2015. The ASRC of mortality was 8.21 per 100 000 (male: 10.08 per 100 000; female: 6.47 per 100 000). The ASRW of mortality was 8.12 per 100 000 (male: 10.01 per 100 000; female: 6.37 per 100 000). When comparing ASRW of colorectal cancer incidence and mortality in different regions stratified by gender, all rates of urban areas were higher than rural areas, and those of eastern areas of China were higher than those of middle areas and the western areas. The differences in rates between the middle areas and the western areas were less than 1 per 100 000. The age-specific rates of incidence and mortality of colorectal cancer all increased with age. The growth trends of different genders were similar. Conclusion: Colorectal cancer is one of the common cancers in China with significant gender and regional differences. The ASRW of incidence among female was higher than the average rate of worldwide. The other ASRW of incidence and mortality were lower than the average rates of worldwide.

Key words: Colorectal cancer, Incidence, Mortality, Cancer Registry, China