The Burden and Risk Factors of Colorectal Cancer in Older Adults From 2010 to 2021: A Systematic Analysis for the Global Burden of Disease Study 2021

INTRODUCTION: Colorectal cancer (CRC) is a highly prevalent cancer type worldwide. The global aging population situation is severe. Research on the disease burden of CRC among the 65+ years elderly population, especially the risk factors, is still insufficient. Studies based on the Global Burden of Disease Study (GBD) database can guide screening and prevention strategies. METHODS: As part of the 2021 GBD Study, we estimated the incidence, mortality, and disability-adjusted life years (DALYs) of CRC by sex and geographic location in the 65+ years elderly population, as well as the number of DALYs due to CRC-related risk factors. RESULTS: In 2021, diet low in whole grains (age-standardized disability-adjusted life years (ASDR), 290.11 [117.98-440.48] per 100,000), diet low in milk (ASDR, 239.69 [64.75-399.12] per 100,000), diet high in red meat (ASDR, 239.02 [-0.08 to 486.82] per 100,000) were the top 3 risk factors contributing to ASDR for both sexes combined globally. From 1990 to 2021, the ASDR for CRC attributable to 10 risk factors decreased for both sexes combined except high body-mass index (average annual percent change, 0.10 [0.02-0.18]). DISCUSSION: Over the past decade, the average annual percent change of age-standardized incidence rate, age-standardized mortality rate, and ASDR of CRC cases among people aged 65 and above globally has shown a downward trend overall, but the burden pattern varies by Socio-demographic Index quintile and GBD region, with an upward trend in middle to low Socio-demographic Index regions. There are differences in the incidence, mortality, and major risk factors of CRC in different regions. Reducing the prevalence of related risk factors is key to reducing CRC DALYs.