A new study, presented at the Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer in Tampa, Florida revealed that bariatric surgery may lower the risk of uterine cancer. Researchers found that obese women, who have undergone bariatric surgery to lose weight, had a 70 percent lower risk of uterine cancer. The risk becomes even lower when the weight is kept off.
Uterine cancer affected approximately 50,000 women in 2013 and is known to be the most common type of cancer of the female reproductive organs; however, obese women are even more prone to uterine cancer. They are two to four times more likely to be affected by it compared to those who have a normal weight.
Kristy Ward, MD, presented the findings of the study during the SGO meeting. She says, “The retrospective analysis of the data proves that obesity increases a woman’s risk of cancer. This new study shows that bariatric surgery is associated with a clinically significant lower risk of uterine cancer, which is in agreement with findings of other studies, for example that the risk of uterine cancer may increase when a woman’s body mass index (BMI) increases.”
For the study, researchers analyzed information of more than seven million admissions for bariatric surgery in women between 2009 and 2013. Of this large group, 103,797 had undergone bariatric surgery previously and 0.4 percent was diagnosed with uterine cancer. Another 832,372 were considered for bariatric surgery and in these women, uterine cancer was diagnosed in nearly 2 percent of the cases. Researchers concluded that obese women, who had not undergone bariatric surgery, were three to four times likely to get uterine cancer compared to those who have had a successful bariatric surgery.
Ward says that the risk of uterine cancer becomes even lower when the weight is kept off after the surgery, but even those who had gained some weight, experienced a 52 percent lower risk compared to those without a history of bariatric surgery.
During the presentation at the SGO meeting, Ward was not able to address the underlying biologic mechanisms by which bariatric surgery lowers the risk of uterine cancer. “The mechanisms remain undetermined for now, but there is some evidence that suggests that bariatric surgery reduces inflammation. This is known to play a big role in the development of any cancer,” she explains. Ward also explained that researchers did not have access to individual patient data in order to evaluate the uterine cancer risk by type of bariatric surgery procedure.
There are several types of bariatric surgery, depending on the patient’s needs. Some limit the amount of food the stomach can hold, others bypass a part of the small intestine, allowing patients to limit their calorie intake. Every year, an estimated 200,000 obese women undergo a bariatric surgery. Although hospitals in the U.S. get much more admissions that than, only those who are significantly overweight, often as much as 100 pounds above the ideal weight, are taken into account for the surgery.
Endometrial cancer, which occurs in the inner lining of the uterus, accounts for 95 percent of uterine cancer and an estimated 50 percent of these can be linked to obesity. The study, confirming that the risk of uterine cancer may be lowered by bariatric surgery, will be published in the April edition of Gynecologic Oncology.
By Diana Herst