Global, regional, and national burden of colorectal cancer attributable to modifiable risk factors, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
Background Colorectal cancer (CRC) represents a major global health burden, with modifiable risk factors including high body-mass index, insufficient physical activity, tobacco use, and dietary risks contributing substantially to its incidence and mortality. However, comprehensive spatiotemporal analyses of this burden, particularly within Brazil, Russia, India, China, and South Africa (BRICS) countries, remain limited. This study aimed to assess the global, regional, and national burden of CRC attributable to these four modifiable risk factors from 1990 to 2021 using Global Burden of Disease Study 2021 data. Methods Data from 204 countries and territories were analyzed to estimate attributable CRC burden, stratified by sex, age, region, and country. Temporal trends were assessed, projections to 2050 were generated using autoregressive integrated moving average and exponential smoothing models, and health inequalities across Socio-demographic index (SDI) levels were evaluated using the Slope Index of Inequality and Concentration Index. Results In 2021, males in BRICS countries exhibited higher attributable CRC burden. Age-standardized rates decreased in high-SDI regions but increased in low-SDI regions. Between 1990 and 2021, absolute attributable CRC cases increased across all BRICS countries, although age-standardized trends varied. Projections indicated continued increases in absolute case numbers in BRICS countries by 2050. Global burden remained concentrated in low-SDI regions, with modest reductions in absolute inequalities but persistent relative inequalities. Conclusions Substantial disparities in CRC burden attributable to modifiable risk factors exist across sociodemographic contexts. Targeted, equity-oriented public health strategies are essential to mitigate the projected burden increase, particularly within BRICS countries, by 2050.