Trends and disparities in mortality from malignant neoplasms of digestive organs and from malignant neoplasms of digestive organs with obesity among U.S. adults aged >45 years from 1999 to 2020 using CDC WONDER data

Background & Objective: Malignant neoplasms of digestive organs are a leading cause of death among U.S. adults, and obesity is a significant risk factor. Although the overall mortality rate for digestive tract cancers has declined nationally, the long-term trends and distribution disparities in obesity-related digestive tract cancer mortality across demographic subgroups remain unclear. This study aims to analyze the trends and disparities in obesity-related digestive tract cancer mortality among U.S. adults aged ≥ 45 years from 1999 to 2020. Methods Data for individuals aged ≥ 45 years with malignant neoplasms of digestive organs (ICD-10 codes: C15-C26) and with obesity (ICD-10 code: E66) listed as causes of death were extracted from the CDC WONDER database. The Joinpoint Regression Program was used to calculate the age-adjusted mortality rate (AAMR) per 100,000 population, annual percent change (APC), average annual percent change (AAPC), and corresponding 95% confidence intervals (CIs). Results Between 1999 and 2020, a total of 3,371,216 deaths from digestive tract cancers occurred among individuals aged ≥ 45 years, of which 7,303 (0.22%) were obesity-related. The overall AAMR for digestive tract cancers decreased significantly [AAPC = -1.08% (95% CI: -1.13, -1.02)]. In contrast, the AAMR for obesity-related digestive tract cancers increased significantly from 0.17 (1999) to 0.48 (2020) per 100,000 [AAPC = 4.62% (95% CI: 3.94, 5.55)]. This increasing trend was consistent across all subgroups but was particularly pronounced among males (AAPC: 5.91%), non-Hispanic Black individuals (AAPC: 4.75%), and residents of rural areas (AAPC: 5.38%). Conclusion During the study period, while the overall mortality rate for digestive tract cancers decreased among U.S. adults aged ≥ 45 years, the mortality rate for obesity-related digestive tract cancers increased sharply, with significant disparities by sex, race/ethnicity, and geography. These findings underscore the urgency of integrating obesity prevention and control as a crucial component of comprehensive strategies for malignant neoplasms of digestive organs control, particularly through targeted interventions in high-risk populations.