Women who lost weight after bariatric surgery (weight loss surgery) significantly trimmed their chances for developing uterine cancer, according to a new study.
The weight loss helped to normalize levels of hormones that have been linked to uterine cancer, according to the researchers behind this study.
"Ask your doctor about minimizing cancer risks."
This study’s lead author was Kristy Ward, MD, the senior gynecologic oncology fellow in the University of California, San Diego School of Medicine's reproductive medicine department.
She and other researchers from that institution, its Moores Cancer Center and the University of Texas School of Public Health investigated the medical records of 7.4 million women who had been treated at a 392 hospitals and university-based medical centers across the country.
The group’s average age was 52, though the youngest patients were 18 years old. By race, 56.6 percent of patients were white, 12.3 percent were black, 8.5 were Hispanic and the remainder were Asian or a Pacific Islander.
Of that 7.4 million, 103,797 had their stomachs and digestive tract reshaped through bariatric surgery to limit their food intake. Also, 44,345 of the 7.4 million had been diagnosed with uterine cancer.
These researchers concluded that, for the entire group of 7.4 million women, the risk of developing uterine cancer was 2.8 times higher among obese women than among women who were not obese.
In addition, obese women who lost weight through bariatric surgery cut their risks of developing uterine cancer by 71 percent. Those who maintained a healthy weight after bariatric surgery lowered their uterine cancer risks by 81 percent.
"In a normal menstruating woman, two hormones control the endometrium (inner lining of the uterus). Estrogen builds up the endometrium and progesterone stabilizes it,” Dr. Ward said in a press statement. “A woman with excess [fat] has an increased level of estrogen because the fat tissue converts steroid hormones into a form of estrogen.”
An overload of estrogen can cause the uterus’ endometrium to grow abnormally, develop tumors and change in ways that may lead to cancer, she added.
Weight loss can help regulate those hormones, Dr. Ward and team wrote. Bariatric surgery is an option of "last resort" for women who are extremely obese and who have such weight-related disorders as diabetes, sleep apnea, heart problems or severe trouble with their joints, these researchers wrote. Successful bariatric patients also tend to follow a disciplined diet and exercise.
"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,” Dr. Ward said.
These researchers also wrote, “In addition, there is the potential that the mechanisms that result in decreased cancer risk may also be effective reducing recurrence risk in women with a history of endometrial cancer.”
Andre Hall, MD, who practices obstetrics and gynecology at Birth & Women's Care in Fayetteville, NC, said Dr. Ward's new research re-emphasizes how "obesity has long been know to be a risk factor for endometrial cancer. Therefore, anything that reduces obesity, including bariatric surgery, would be expected to reduce the risk of this cancer ... This is yet another in a long list of reasons to maintain a healthy diet and to get regular exercise in an attempt to maintain normal weight."
This study was published online March 22 in Gynecologic Oncology.
The researchers had open access to the data and were not separately funded for this study.
The researchers reported that they had no financial or ethical conflicts of interested related to this study.