Global trends in gastric and colorectal cancer, 1990 to 2021: A population-based observational study using GBD 2021 data.

Gastric and colorectal cancers are among the most prevalent gastrointestinal malignancies worldwide and represent significant global public health concerns. Their epidemiological profiles vary substantially across regions and sociodemographic contexts. Despite advances in screening and treatment, both types of cancer continue to cause considerable morbidity and mortality. A comprehensive understanding of these temporal trends and future trajectories is critical for developing effective cancer control policies. Data from the Global Burden of Disease Study 2021 were used to systematically evaluate age-standardized incidence rates (ASIRs), prevalence rates, mortality rates (ASMRs), and disability-adjusted life-year rates for gastric and colorectal cancers between 1990 and 2021. Temporal trends were assessed using joinpoint regression and ARIMA models. Decomposition analysis was performed to differentiate among the effects of population growth, aging, and epidemiological changes. Finally, trend-based projections of the global burden through 2050 were performed. Between 1990 and 2021, both ASIR and ASMR for gastric cancer declined globally, particularly in high Socio-demographic Index countries. Conversely, colorectal cancer demonstrated an increasing trend in ASIR and age-standardized prevalence rates, although ASMR and disability-adjusted life-year rates decreased. Countries with a high Socio-demographic Index exhibited a higher incidence of colorectal cancer but benefited from lower mortality, likely reflecting differences in healthcare capacity. Males experienced a consistently higher burden of both cancers. Trend-based projections suggest a continued decline in the burden of gastric cancer, whereas the incidence of colorectal cancer may remain relatively stable or increase modestly, with mortality continuing to decline. Despite declining mortality rates, gastric and colorectal cancers remain a substantial global health burden, with distinct epidemiological patterns. Enhancing early detection strategies, such as gastroscopy and colonoscopy, along with dietary modifications and Helicobacter pylori eradication in high-risk populations, may help mitigate the future disease burden and inform health policy interventions.