Global, regional, and national burden of smoking-attributable digestive cancers in adults aged ≥60 years, 1990–2021, with projections to 2036: A secondary dataset analysis of Global Burden of Disease (GBD) 2021

INTRODUCTION: Smoking is a key driver of esophageal, stomach, liver, pancreatic, and colorectal cancers, and its impact is stronger in adults aged ≥60 years due to cumulative exposure and population aging. A comprehensive analysis of temporal trends and sociodemographic drivers for major digestive cancers in this population is lacking. This study quantified smoking-attributable deaths and disability-adjusted life years (DALYs) from digestive cancers in adults aged ≥60 years globally from 1990 to 2021. It also projected future burdens to 2036 to inform age-focused tobacco control and cancer prevention. METHODS: This study is a secondary dataset analysis of data from GBD 2021. We analyzed smoking-attributable deaths and DALYs for esophageal, stomach, liver, pancreatic, and colorectal cancers among adults aged ≥60 years across 204 countries and territories (1990-2021). We decomposed temporal changes into contributions from population growth, aging, and changes in age-specific rates. Associations with the sociodemographic index (SDI) were assessed, and future burdens (2022-2036) were projected using a Bayesian age-period-cohort model. RESULTS: From 1990 to 2021, global smoking-attributable deaths increased by 27.5% (398426 to 508147) and DALYs by 14.6% (8.9 to 10.2 million). Decomposition attributed the increase primarily to population growth (41-43%), partially offset by declining age-specific rates (-30% to -35%). Regional disparities were stark: high-SDI regions stabilized burdens through epidemiological improvements, while low-SDI regions saw population-driven escalations. SDI was positively correlated with burden at the country level (ρ=0.20-0.48; p