Intentional Weight Loss in Postmenopausal Women May Be Linked to Reduced Endometrial Cancer Risk


Key Points

  • Women who intentionally lost weight saw a significant decrease in their risk for endometrial cancer compared with women whose weight remained stable. Among women who lost 5% or more of their body weight after age 50, risk for endometrial cancer was 29% lower, regardless of their age or how much weight they lost.
  • Women with obesity who intentionally lost 5% or more of their body weight had a 56% reduction in their risk for endometrial cancer. In addition, women who were overweight or obese and achieved a normal BMI after intentional weight loss had the same risk as women who maintained a normal BMI. Conversely, those who gained more than 10 pounds had a 26% higher risk for endometrial cancer.
  • The study findings should motivate programs for weight loss in postmenopausal women with obesity.

Although many studies have linked obesity with an increased risk for endometrial cancer, information about the influence of weight loss on the cancer in postmenopausal women has been limited. Now, a study by Luo et al evaluating the association of weight change and endometrial cancer risk among postmenopausal women has found that intentional weight loss could decrease the risk of endometrial cancer by as much as between 29% and 56%. In addition, women who were overweight or obese and achieved a normal body mass index after intentional weight loss had the same risk for the cancer as women who had maintained a normal body mass index. The study was published in the Journal of Clinical Oncology.

Study Methodology

The researchers analyzed data from 36,794 women enrolled in the Women’s Health Initiative (WHI) Observational Study. Nearly 162,000 women aged 50 to 79 were recruited into the study throughout the United States between 1993 and 1998. The researchers measured participants’ weight at the beginning of the study and again 3 years later to calculate change in body weight.

Women who had lost weight were asked whether their weight loss was voluntary or involuntary. Involuntary or unintentional weight loss is usually associated with other comorbidities or illnesses, and these patients typically have poorer outcomes, which may affect the research findings. The researchers then followed the participants for 11.4 years. During that time, 566 endometrial cancer occurrences were confirmed by medical record review.

Multivariable Cox proportional hazards regression models were used to evaluate relationships (hazard ratios [HRs] and 95% confidence intervals [CIs]) between weight change and endometrial cancer incidence.

Study Results

In multivariable analyses, compared with women who had stable weight (± 5%), women with weight loss had a significantly lower endometrial cancer risk (HR = 0.71; 95% CI = 0.54–0.95). The association was strongest among obese women with intentional weight loss (HR = 0.44; 95% CI = 0.25–0.78). Weight gain (≥ 10 pounds) was associated with a higher endometrial cancer risk than was stable weight, especially among women who had never used hormone replacement therapy.

Weight Loss and the Potential for Reducing Cancer Risk

In a statement, ASCO Expert in Cancer Prevention, Jennifer A. Ligibel, MD, said: “There have been more than a thousand studies linking obesity to an increased risk of endometrial and other cancers, but almost none that look at the relationship between weight loss and cancer risk. This study tells us that weight loss, even later in life, is linked to a lower risk of endometrial cancer. The findings also support the development of weight loss programs as part of a cancer prevention strategy in overweight and obese adults.” Dr. Ligibel is not affiliated with this study. “These findings should motivate programs for weight loss in obese postmenopausal women,” concluded the study authors.

Juhua Luo, PhD, of the Department of Epidemiology and Biostatistics at Indiana University, is the corresponding author of this study.

Disclosures provided by the authors are available at

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.