Bariatric surgery decreased risk of uterine cancer by up to 81 percent in severely obese women, a new study finds.
Obesity is a growing health issue in the United States with over two-thirds of country's population being obese or overweight. This weight disorder is linked to a host of other problems including heart disease, diabetes and cancer, in particular uterine cancer. A new study finds that bariatric surgery may significantly reduce the risk of this type of cancer in severely obese women.
Researchers found that a bariatric surgery lowers the risk of uterine cancer by 71 percent and up to 81 percent in severely obese women. The findings were based on a retrospective cohort study of 7,431,858 patients in the University HealthSystem Consortium database, which contains information from contributing academic medical centers in the United States and affiliated hospitals. Of this total, 103,797 patients had a history of bariatric surgery and 44,345 had a diagnosis of uterine malignancy.
There are many biological mechanisms that link obesity to uterine cancer. Excessive adipose or fat tissue raises circulating levels of estrogen, which is associated with tumor creation and metastasis. Obesity also causes chronic inflammation, boosting insulin resistance and increased estrogen levels.
"The majority of endometrial cancers are estrogen-driven," first author Kristy Ward from UC San Diageo, said in a press statement. "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."
"So there is too much estrogen, causing the endometrium to build up, but not enough progesterone to stabilize it. The endometrium continues to grow and can undergo changes into abnormal tissue, leading to cancer."
A bariatric surgery facilitates normal hormone levels, decreases inflammation, and drops insulin resistance. Weight loss due to this surgery also allows patients to take part in more physical activity, improving their overall health.
This surgery typically reduces the size of the stomach using a constrictive gastric band, removing a portion of the stomach or resecting and re-routing the small intestines to a small stomach pouch. It is often considered as the last resort for obese patients after all other non-surgical weight loss efforts fail. There are a few criteria patients should meet in order to be eligible for a bariatric surgery. First, they should accept the surgical risks and secondly they should be defined as either severely obese with a BMI of 40 or greater or have a BMI of 35 or greater with at least one related condition like diabetes, obstructive sleep apnea, obesity-related cardiomyopathy or heart muscle disease or severe joint disease.
"The obesity epidemic is a complicated problem," she said. "Further work is needed to define the role of bariatric surgery in cancer care and prevention, but we know that women with endometrial cancer are more likely to die of cardiovascular causes than they are of endometrial cancer. It's clear that patients who are overweight and obese should be counseled about weight loss, and referral to a bariatric program should be considered in patients who meet criteria."
According to National Cancer Institution estimates, 52,630 new cases of uterine cancer will be diagnosed this year. About 8,590 women will die from cancers of the uterine body. The average chance of a woman being diagnosed with this cancer during her lifetime is about one in 37. There are over 600,000 women who are survivors of this cancer. This cancer is slightly more common in white women but black women are more likely to die from it.
Findings of the study were published in the April issue of Gynecologic Oncology.
