Bariatric Surgery May Resolve Precancerous Uterine Lining Changes in Obese Women
A study evaluating the effects of bariatric surgery on obese women most at risk for cancer has found that the weight-loss surgery slashed participants' weight by one-third and eliminated precancerous uterine growths in those who had them. Other effects included improving patients' physical quality of life; improving their insulin levels and ability to use glucose (which may reduce their risk for diabetes); and even altering the composition of their gut bacteria. The findings were published by Modesitt et al in Gynecologic Oncology.
The study speaks both to the benefits of bariatric surgery and to the tremendous toll obesity takes on health. “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 United States,” said Susan C. Modesitt, MD, of the University of Virginia Cancer Center (UVA). “When you're looking at obesity-related cancers, the biggest one is endometrial cancer, but also colon cancer, breast cancer, renal cancer, and gallbladder cancer. We think about 40% to 50% of all endometrial cancer, which is in the lining of the uterus, is caused by obesity.”
Study Details
The study looked at 71 women with a mean age of 44.2 years and a mean body mass index (BMI) of 50.9. Women are considered obese at a BMI of 30, and morbidly obese at 40, yet almost one-third of women presenting for bariatric surgery did not identify themselves as obese.
The study looked at the effects of bariatric surgery in a relatively short time frame—1 to 3 years after surgery. A total of 68 participants underwent the procedure; two opted out of the surgery, and another died of a heart condition prior to surgery. The effects of surgery on body weight were dramatic: Mean weight loss was more than 100 pounds.
Of study participants, 10% who had not had a hysterectomy showed precancerous changes in the lining of the uterus, and all of them resolved with weight loss. “We're talking about small numbers, really tiny numbers,” of study participants, said Dr. Modesitt, noting one limitation of the study. “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.”
Dr. Modesitt, Director of the Gynecologic Oncology Division and the Richard N. and Louse R. Crockett Professor in the Obstetrics and Gynecology Department at UVA, was most surprised by the dramatic changes seen in the patients' metabolic profiles derived from the gut microbiome. “The study results demonstrate that there is a huge alteration, 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…. 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.”
Although the study speaks to the transformative effect bariatric surgery can have, Dr. Modesitt urged people to avoid gaining weight in the first place—and for those seeking to lose weight, to exercise and eat more healthily before turning to surgery. “We really should be working on diet and exercise from the get-go in our entire society, starting with our children. And exercise does seem to be protective—even if you don't lose all the weight, it absolutely has beneficial effects,” she concluded.
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®.
