Rising trends in obesity and cancer-related mortality in the United States: a population-based analysis, 1999-2020

Context: Obesity is a known risk factor for various cancers. Despite the growing prevalence of obesity in the United States, national-level trends in obesity-associated cancer mortality remain insufficiently quantified. Objective: To evaluate national trends in cancer mortality where obesity was listed as a contributing or underlying cause of death from 1999 to 2020. Methods: A retrospective cross-sectional study was conducted using publicly available mortality data from the CDC WONDER database. Adults aged 25 years and older were included if both obesity (ICD-10: E66) and cancer (ICD-10: C00-D9) were listed on their death certificates. Age-adjusted mortality rates (AAMRs) were calculated per 1 000 000 population, and Joinpoint regression was used to assess temporal trends through annual percent change (APC) and average annual percent change (AAPC). Results: A total of 33 572 obesity and cancer-related deaths were recorded. The overall AAMR rose from 3.73 in 1999 to 13.52 in 2020, with an AAPC of 5.92%. The highest mortality rates were observed in older adults, women, rural populations, and racial minorities, particularly Black and American Indian individuals. Breast, prostate, and lung cancers accounted for the greatest burden. A marked rise occurred between 2018 and 2020 across all subgroups. Conclusion: Obesity and cancer-related mortality in the United States has more than tripled over 2 decades, with notable disparities across demographic groups. These findings highlight the need for targeted public health efforts that integrate obesity prevention into cancer control strategies.