A study evaluating the effects of bariatric surgery on obese women most at risk for cancer has found that the bariatric surgery eliminated precancerous uterine growths in those that had them. Other effects included substantial weight loss, improving patients’ physical quality of life (QoL), improving their insulin levels and ability to use glucose, and altering the composition of their gut bacteria. The study, ‘Women at extreme risk for obesity-related carcinogenesis: Baseline endometrial pathology and impact of bariatric surgery on weight, metabolic profiles and quality of life.’, was published in in the journal Gynecologic Oncology.
“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 US,” said Dr Susan C Modesitt of the University of Virginia Cancer Center. “When you’re looking at obesity-related cancers, the biggest one is endometrial cancer, but also colon cancer, breast cancer, renal cancer and gall bladder cancer. We think about 40 to 50 percent of all endometrial cancer, which is in the lining of the uterus, is caused by obesity.”
The study researchers sought to determine baseline endometrial histology in morbidly obese women undergoing bariatric surgery and to assess the surgical intervention’s impact on serum metabolic parameters, QOL and weight.
The study included 71 women undergoing bariatric surgery and their demographic and clinicopathologic data, serum, and endometrium (if no prior hysterectomy) were collected preoperatively and serum collected postoperatively. Serum global biochemical data were assessed pre/postoperatively. The mean age of women was 44.2 years and a mean BMI50.9, interestingly a third of women presenting for bariatric surgery did not identify themselves as obese. A total of 68 participants underwent the procedure; two opted out of the surgery, and another died of a heart condition prior to surgery.
Following surgery, the mean weight loss was 45.7kg and the endometrial biopsy results showed that ten percent of study participants who had not had a hysterectomy showed precancerous changes in the lining of the uterus, and all of those resolved with weight loss (proliferative (13/30; 43%), insufficient (8/30; 27%), secretory (6/30; 20%) and hyperplasia (3/30; 10%—1 complex atypical, 2 simple).
In addition, QoL data showed significant improvement in physical component scores (PCS means 33.9 vs. 47.2 before/after surgery; p<0.001). Twenty women underwent metabolic analysis which demonstrated significantly improved glucose homeostasis, improved insulin responsiveness, and free fatty acid levels. Significant perturbations in tryptophan, phenylalanine and heme metabolism suggested decreased inflammation and alterations in the intestinal microbiome. Most steroid hormones were not significantly impacted with the exception of decreased DHEAS and 4-androsten metabolites.
“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,” said Modesitt. “For example, before ground breaking work by Dr John Marshall at UVA in the past, no one knew that ulcers were from bacteria. 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.”
While the study speaks to the transformative effect bariatric surgery can have, 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 said. “There are lots of studies showing if you exercise, it improves your insulin, your glucose, all of those sorts of things that go along with the cancer-causing effect. Almost everybody agrees adding exercise would be wonderful and improve health on many levels. But losing excess weight would also be good.”