Associations of life course obesity with endometrial cancer: could alternative categorization of BMI change improve inference about cumulative risks?

This article focuses on evaluating the analytic approach used to assess life course changes in body mass index (BMI) and their association with endometrial cancer (EC) risk, based on a pooled analysis from the Epidemiology of Endometrial Cancer Consortium. The authors critique the original categorization of BMI change from young adulthood (ages 18–21) to later adulthood (mean age ~63–65), arguing that grouping all individuals who maintain or gain obesity into a single category obscures differences in cumulative exposure and risk. They propose a more detailed analytic framework using indicator variables for all nine possible BMI category transitions (underweight/normal, overweight, obese) between the two time points, which could yield more nuanced odds ratios and improve understanding of how weight trajectories influence EC risk. While acknowledging limitations such as sample size requirements and loss of sensitivity to small BMI changes, the authors suggest that this refined approach could have important clinical and public health implications for targeting weight management strategies across the life course.