Individuals who gain the highest amounts of weight in adulthood are at significantly greater risk for developing certain obesity-related cancers, according to findings from a pooled cohort study presented at the European Congress on Obesity 2026 (Abstract 0759; AD16.04). The findings were also published as a preprint in medRvix.
“Both early adult body weight and weight gain across adulthood were associated with the risk of most established and some potentially obesity-related cancers, with differences by cancer site, sex, and timing of weight gain. In the context of the rising prevalence of obesity and cancer in Western countries and globally, the findings highlight the importance of a life-course perspective on weight management for cancer prevention,” the study authors stated.
Background and Study Methods
Research has proven that excess body weight is associated with esophageal, gastric, colorectal, liver, gallbladder, pancreatic, postmenopausal breast, endometrial, ovarian, renal, and thyroid cancers, as well as multiple myeloma. A majority of studies have focused on weight at a particular point in time or changes between two time points rather than on body weight trajectories.
Researchers conducted a pooled, nationwide cohort study in Sweden to explore the association between body weight trajectories for individuals aged 17 to 60 and site-specific cancer incidence. They collected data from the ODDS study with weight data for 1911 to 2020, with follow-up for cancer incidence through 2023. The cohort study included individuals with an average of four weight measurements between ages 17 and 60 years (n = 630,022).
Key Findings
Individuals with weight changes in the fifth quintile were at heightened risk for many cancers in comparison to individuals with weight changes in the first quintile. The strongest association was esophageal adenocarcinoma in men (hazard ratio [HR] = 2.25; 95% confidence interval [CI] = 1.66–3.04), liver cancer in men (HR = 2.67; 95% CI = 2.15–3.33), endometrial cancer in women (HR = 3.78; 95% CI = 3.09–4.61), and pituitary tumors in both sexes (in men, HR = 3.13; 95% CI = 2.13–4.61; in women, HR = 2.13; 95% CI = 1.41–3.22).
The researchers found that associations varied by sex and age. Heavier weight at age 17 years and earlier onset of obesity were also associated with a higher incidence of cancer.
“Steeper increases in body weight between ages 17 and 60 were associated with higher incidence of several established obesity-related cancers, as well as some for which previous evidence linking obesity to cancer is more limited. Associations were particularly pronounced for liver cancer and esophageal adenocarcinoma among men, endometrial cancer among women, and renal cell carcinoma and pituitary tumors in both sexes.”
The researchers noted that the findings stress that a life-course approach to weight management is needed, as well as sex- and age-targeted cancer prevention strategies.
DISCLOSURES: The work was funded by the Swedish Cancer Society, Swedish Research Council, Mrs. Berta Kamprad’s Cancer Foundation, and the Malmö General Hospital Cancer Foundation. The researchers acknowledge the national research infrastructure SIMPLER for generating and making data and resources available. SIMPLER receives funding from the Swedish Research Council (to Uppsala University and Karl Michaëlsson). The authors declare no conflict of interest.
