Precancerous uterine growths eliminated after bariatric surgery in obese women

A study of bariatric surgery among obese women at risk for uterine cancer has found that the procedure resulted in the elimination of precancerous uterine growths as well as an average weight loss of 100 lbs.

Other effects of bariatric surgery included improving physical quality of life, insulin levels, ability to use glucose, and even altering the composition of gut bacteria, according to a study published in the August issue of Gynecologic Oncology.

The study underscores the benefits of bariatric surgery and the tremendous toll obesity takes on health, the researchers emphasized.

About 40% to 50% of all endometrial cancer is caused by obesity, estimated Susan C. Modesitt, MD, of the Division of Gynecologic Oncology at the University of Virginia Cancer Center, in Charlottesville, VA, and the study’s corresponding author. “If you look at cancers in women, about a fifth of all cancer deaths would be prevented if we had women at normal body weight in the U.S.,” she said.

In this study, Dr. Modesitt and colleagues enrolled 68 women (average age: 44.2) who underwent bariatric surgery. Before surgery, their mean body mass index (BMI) was 50.9. (In women, a BMI of 30 is considered obese and a BMI of 40 is considered morbidly obese.)

The study looked at the effects of bariatric surgery within 1 to 3 years after surgery. Mean weight loss was significant—45.7 kg (more than 100 lbs). Patients also reported significantly improved physical quality of life.

Prior to surgery, 10% of study participants showed precancerous endometrial hyperplasia changes, all of which resolved with weight loss. The small number of participants in the study limited the researchers from concluding that bariatric surgery eliminated the hyperplasia, Dr. Modesitt said. “So I could never say that effect is definitive, but it is suggestive, given that we know already the incredibly strong link between endometrial cancer and obesity,” she added.

Most surprising were the dramatic changes that occurred in patients’ metabolic profiles of the gut microbiome, including beneficial changes in glucose homeostasis, insulin responsiveness, and inflammation.

“The study results demonstrate that there is a huge alteration [in the gut microbiome], but I don’t even know what to say about that, except it is really new and intriguing area to look at in the link between obesity and cancer,” Dr. Modesitt said. “Who knows what role the gut bacteria play in promoting obesity, but metabolic parameter/markers of the bacteria definitely changed after [study participants] lost weight.”