Trends in the age-related incidence of colon and rectal cancers in China, 2005-2015

Background: Recent evidences showed that the incidence of colorectal cancer decreased among older adults, yet this decline didn't appear in adults younger than 50 years. Our aim was to evaluate age-related incidence trends of colon and rectal cancers in China during 2005-2015. Methods: A retrospective study of colon and rectal cancers was conducted using population-based data from the Chinese Cancer Registry Annual Report . Age at diagnosis was analyzed in five sub-groups (0- 19, 20-34, 35-49, 50-64 and 65 years). Data including new cases, incidence, and age-standardized rates (ASRs) were classified by sex and area. Temporal trends of ASRs were determined with Joinpoint regression analysis. Results: From 2005 to 2015, colon cancer incidence decreased by -2.2% (95%CI: -3.1, -1.3) per year. A more steady decrease was seen in rectal cancer with AAPC of -0.9% (95%CI: -1.4, -0.4). Stratified by age at diagnosis, incidence trends followed a similar pattern, without age-related disparity. Females showed pronounced declines relative to males. The exception was that rural individuals showed opposite increasing trends, with 2.7% of AAPCs for colon cancer and 2.0% for rectal cancer. Conclusion: A slight decline was observed in colon and rectal cancers during 2005-2015, regardless of age at diagnosis. (c) 2021 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Automated summary

From 2005 to 2015, there was a slight decline in the incidence of colon and rectal cancers in China, with no significant age-related disparity. Females showed more pronounced declines compared to males. However, rural residents exhibited increasing trends in both colon and rectal cancer incidence.