Prospective Cohort Study of Pre- and Postdiagnosis Obesity and Endometrial Cancer Survival.

Background: Disease-free survival (DFS) and overall survival (OS) associations with anthropometric measures of obesity and changes in these exposures remain unknown among endometrial cancer survivors.

Methods: Endometrial cancer survivors diagnosed between 2002 and 2006 completed direct anthropometric measurements and self-reported lifetime weight history during in-person interviews approximately 4 months after diagnosis (peridiagnosis) and approximately 3 years after diagnosis (follow-up). Participants were followed-up until death or March 20, 2019. Cox proportional regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for body mass index (BMI), weight, waist circumference, and waist-hip ratio with DFS and OS. Statistical tests were 2-sided.

Results: A total of 540 and 425 cancer survivors were assessed peridiagnosis and follow-up, respectively. During the median 14.2 years of follow-up (range = 0.3-16.5 years), 132 participants had a recurrence and/or died (DFS), with 111 deaths overall (OS). Reduced DFS was noted with greater recalled weight 1 year before diagnosis (HR = 1.88, 95% CI = 1.15 to 3.07), BMI 1 year before diagnosis (HR = 1.88, 95% CI = 1.09 to 3.22), and measured peridiagnosis BMI (HR = 2.04, 95% CI = 1.18 to 3.53). Measured peridiagnosis waist circumference of at least 88 cm was associated with decreased DFS (HR = 1.94, 95% CI = 1.24 to 3.03) and OS (HR = 1.90, 95% CI = 1.16 to 3.13). A twofold decrease in DFS and OS was associated with a BMI of at least 5% or weight change from 1 year before diagnosis to peridiagnosis. No associations were observed for the assessment during follow-up.

Conclusions: One-year before- and peridiagnosis anthropometric measures of obesity were associated with reduced survival among endometrial cancer survivors. Anthropometric changes from 1 year before to peridiagnosis may provide an important indication of future survival in this population.