Adult weight gain associated with increased risk for endometrial cancer

Women who gained substantial amounts of weight were at increased risk for endometrial cancer regardless of BMI, according to results from a prospective cohort study conducted by the American Cancer Society.

Researchers also found that weight cycling, also known as "yo-yo" dieting, had no effect on cancer risk.

Victoria L. Stevens, PhD, strategic director of laboratory services at the ACS in Atlanta, presented results from the ACS Cancer Prevention Study II (CPS-II) Nutrition Cohort at the 10th AACR International Conference on Frontiers in Cancer Prevention Research. She said researchers had expected to find that women who repeatedly gain and lose weight were at increased risk because fat tissue is the major source of circulating estrogen in postmenopausal women; estrogen promotes the development of endometrial cancer; and women whose weight fluctuates have a higher proportion of fat.

Victoria L. Stevens, PhD

"Weight gain during adulthood may increase risk for endometrial cancer in postmenopausal women, but weight cycling, which results from unsuccessful attempts to lose weight, does not increase risk for this cancer," Stevens said in a press release. "Weight gain during adulthood should be avoided to minimize risk for endometrial cancer. Women who have gained weight and are overweight or obese should continue to attempt to lose weight, even though most weight loss will not be maintained."

Stevens and colleagues found that total adult weight gain had a statistically significant association with risk for endometrial cancer. The HR was 3.93 (95% CI, 2.73-5.65) for a woman who gained at least 61 lb compared with a woman whose weight remained stable. The association remained, even after researchers corrected for baseline BMI (HR=1.92; 95% CI, 1.20-3.07).

Weight cycling appeared to be associated with increased risk for endometrial cancer for women who had 10 or more cycles compared with no cycles (HR=2.10; 95% CI,1.61-2.74), but the association disappeared after correcting for baseline BMI (HR=1.02; 95% CI, 0.75-1.39).

The study evaluated 38,152 women with an intact uterus who provided information on weight history and weight cycling on a baseline questionnaire. There were 560 women in the cohort diagnosed with endometrial cancer from 1992 to 2007. Adult weight change was calculated from the reported weight at age 18 years and current weight on the questionnaire. Researchers determined the number of lifetime weight cycles based on the number of times a patient lost and later regained at least 10 lb.

For more information:

Stevens VL. #A77. Presented at: 10th AACR International Conference on Frontiers in Cancer Prevention Research; Oct. 22-25, 2011; Boston.

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