[Analysis of the incidence and age characteristics of colorectal cancer in cancer registration areas of Jiangsu Province from 2009 to 2019].

Objective: To analyze the trend of colorectal cancer incidence and age changes in cancer registration areas of Jiangsu Province from 2009 to 2019. Methods: Based on the continuous and complete data of 16 cancer registries with qualified quality control in Jiangsu Province from 2009 to 2019, the crude incidence rate, age-standardized incidence rate by Segi World Standard Population (ASIRW), age-specific incidence rate, mean age at onset, standardized mean age at onset, standardized age-specific incidence proportion, and incidence proportion of the population over 60 years old of colorectal cancer were calculated. Joinpoint software was used to calculate the average annual percentage change (AAPC) of crude incidence rate, ASIRW, age-specific incidence rate, and incidence proportion of the population over 60 years, respectively. Birth cohort models were constructed to analyze the incidence of colorectal cancer and its trends in the population born from 1929 to 2019. Linear regression models were used to analyze the correlation between mean age at onset, standardized mean age at onset and the year of onset. Results: From 2009 to 2019, a total of 48 036 new cases of colorectal cancer were collected from 16 cancer registries in Jiangsu Province, including 27 508 males and 20 528 females. The crude incidence rate and ASIRW of colorectal cancer in Jiangsu Province increased from 19.00/100 000 and 12.32/100 000 in 2009 to 33.49/100 000 and 16.75/100 000 in 2019, respectively, showing a significant upward trend (CR: AAPC=5.99%, ASIRW: AAPC=3.54%, P<0.001). The increase of ASIRW was greater in males than that observed in females (males: AAPC=4.31%, females: AAPC=2.34%, P<0.001), and greater in rural areas than in urban areas (rural areas: AAPC=4.03%, urban areas: AAPC=3.13%, P<0.001). The incidence of people over 50 years old increased significantly by year, with the 60~69 age group exhibiting a more rapid increase (AAPC=4.97%, P<0.05). In the birth cohort, the incidence increased rapidly in the population over 50 years with the passage of birth year, with AAPCs ranging from 1.76% to 7.05% (P<0.05). From 2009 to 2019, the standardized mean age at onset of colorectal cancer increased by 0.10 years annually. The proportion of standardized age-specific incidence exhibited a trend of increase in older age groups, and the incidence proportion of the population over 60 years old showed a significant yearly increase (AAPC=0.86%, P<0.001). Conclusion: From 2009 to 2019, the incidence, mean age at onset and the incidence proportion of the population over 60 years old of colorectal cancer in Jiangsu Province could exhibit a rapid upward trend. The increase is particularly pronounced in males and rural areas. Additionally, the age-specific incidence distribution reveals a trend of increase in older age groups. Therefore, targeted adjustments and comprehensive prevention measures should be strengthened.