A new study out of the University of California, San Diego, School of Medicine and Moores Cancer Center has found that bariatric surgery among severely obese women reduces the risk of endometrial — or uterine — cancer by 71 percent. The risk is reduced by 81 percent if the women are able to stay at a normal weight after their surgery.

“Estimating from various studies that looked at increasing BMI and endometrial cancer risk, a woman with a Body Mass Index (BMI) of 40 would have approximately eight times greater risk of endometrial cancer than someone with a BMI of 25,” Dr. Kristy Ward, an author of the study and senior gynecologic oncology fellow at the Department of Reproductive Medicine at UC San Diego School of Medicine, said in a press release. “This risk likely continues to go up as BMI goes up.”

Bariatric surgery is the process of making the stomach of a severely obese person much smaller by using a gastric band, removing part of the stomach, or re-adjusting a person’s small intestines to make a stomach pouch. Though it may seem like an “easy way out,” patients who undergo bariatric surgery must also follow through on their own lifestyle changes to ensure the weight loss is successful. This means eating healthier and taking part in more physical activity.

In order to be accepted for undergoing bariatric surgery, patients must have a BMI of 40 or greater, or have a BMI of 35 or greater with one of the following conditions: diabetes, obesity-related cardiomyopathy, obstructive sleep apnea, heart muscle disease or severe joint disease.

Obesity has been linked to endometrial cancer because excessive fat tissue contributes to an increase in estrogen, which in turn is associated with tumors and metastasis. Chronic inflammation is also caused by obesity, which boosts levels of estrogen and insulin resistance. “The majority of endometrial cancers are estrogen-driven,” Ward said in the press release. “In a normal menstruating woman, two hormones control the endometrium (inner lining of the uterus). Estrogen builds up the endometrium and progesterone stabilizes it. A woman with excess adipose tissue has an increased level of estrogen because the fat tissue converts steroid hormones into a form of estrogen.” This ultimately leads to a build-up of the endometrium and not enough progesterone to stabilize it.

However, after bariatric surgery, women have been shown to have normalized hormone levels, a decrease in inflammation and insulin resistance, as well as an increase in overall health and physical activity. Not to mention that weight loss can reverse type 2 diabetes and other obesity-related diseases.

A previous study found that weight loss can cut down on the risk for other types of cancer as well. Obesity is actually a risk factor for colon, breast, endometrial, kidney and esophageal cancers. "Evidently, one or several risk factors for cancer are favorably influences by bariatric surgery in women," Dr. Lars Sjöström, lead author of the study, told CNN.