Endometrial cancer risk among younger, overweight women

To examine the risk for endometrial cancer among overweight women using the World Health Organization's clinical definitions of obesity based on body mass index (BMI).

Conducted in the early 1980s, the Cancer and Steroid Hormone study was a multicenter, population-based, case-control study of breast, ovarian, and endometrial cancers among women aged 20-54 years. Participants for the case group (n=421) were identified through cancer registries and had histologically confirmed endometrial cancer. Participants for the control group (n=3,159) were chosen by random-digit dialing methods in the same regions as those in the case group. Those in the case and control groups responded to the same questions during in-person interviews. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

The relationship between endometrial cancer and BMI (calculated as weight [kg]/[height (m)]) was modified by age at last menstrual period (LMP). Of women who were younger than 45 years at LMP, those with BMIs of at least 35.0 had a greater risk of endometrial cancer (56%, 30/54) than did those with normal BMIs (4%, 59/1,492, adjusted OR 21.7, 95% CI 11.3-41.7). Of women age 45 or older at LMP, those with BMIs of at least 35.0 also had a greater risk (40%, 24/60) than did those with normal BMIs (14%, 168/1,235, adjusted OR 3.7, 95% CI 2.0-6.6). Women younger than 45 years at LMP and those with BMIs of at least 25.0 at 18 years and as adults (25%, 31/123) had an approximately sixfold increased risk (adjusted OR 5.8, 95% CI 3.4-9.8) compared with those with normal BMIs at 18 and as adults (4%, 58/1,460).

Very obese women aged 20-54 years have an elevated endometrial cancer risk, which appears heightened by early menopause.

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