Cancer Risks Drop After Bariatric Surgery
People who weighed enough to have severe obesity lowered their risk of developing cancer by 33 percent after having bariatric surgery, researchers found at University of Cincinnati College of Medicine. The benefit was greatest for cancers that are associated with obesity.
“We found having bariatric surgery is associated with a reduced risk of cancer, especially obesity-associated cancers including postmenopausal breast cancer, endometrial cancer, pancreatic cancer and colon cancer,” said Daniel Schauer, MD, associate professor in the UC Division of General Internal Medicine and lead researcher. “What’s surprising is how great the risk of cancer was reduced.”
The findings were recently published online in the Annals of Surgery.
Roughly 15 million adults nationwide have severe obesity. Severe obesity is when your body mass index is greater than 35.
In recent years, researchers have linked obesity and cancer. In fact, obesity is associated with up to 40 percent of all cancers diagnosed in the United States. Overweight and obesity are associated with an increased risk of 13 different types of cancer.
Although many people are aware of how being overweight can affect their risk for heart disease and diabetes, health authorities worry less is known about obesity’s link to cancer. The International Agency for Research on Cancer has identified 13 cancers associated with overweight and obesity:
- multiple myeloma
- adenocarcinoma of the esophagus
- cancers of the thyroid
- postmenopausal breast
- rectum (colorectal)
In the study, researchers looked at data from more than 85,000 patients. More than 22,000 were people who had bariatric surgery. Eight out of 10 patients in the study were women.
Patients undergoing bariatric surgery had a 33 percent lower risk of developing any cancer during follow-up, according to the published findings. Schauer said the benefit was greatest among obesity-associated cancers. The risk of postmenopausal breast cancer dropped by 42 percent and while the risk for endometrial cancer dropped 50 percent in severely obese patients. The risk of colon cancer dropped 41 percent while the risk of pancreatic cancer was lowered by 54 percent.
Cancer risks: estrogen levels
“Cancer risks for postmenopausal breast cancer and endometrial cancer are closely related to estrogen levels,” Schauer said. “Having weight loss surgery reduces estrogen level.”
Bariatric surgery helps reduce the risk of diabetes and insulin levels which may be a risk factor for pancreatic cancer, while the mechanisms for colon cancer are more complicated, Schauer said.
“I think considering cancer risk is one small piece of the puzzle when considering bariatric surgery, but there are many factors to consider. Reductions in diabetes, hypertension and improvements in survival and quality of life are reason enough,” says Schauer. “The study provides an additional reason to consider bariatric surgery.”
Source: University of Cincinnati Academic Health Center news release