Bariatric Surgery Lowers Cancer Risk By a Third,
Even More for Obesity-Associated Cancers


Published in October Issue             

Patients with severe obesity who undergo bariatric surgery lowered their risk of developing any cancer by a third, and obesity-associated cancers by more than 40 percent, according to a new study published online in Annals of Surgery.

Findings of the National Cancer Institute of the National Institutes of Health (NIH)-funded study echo previous research that demonstrates the effect weight loss and bariatric surgery have on reducing the incidence of cancer – the second leading cause of death in the
United States.

"What's surprising is how great the risk of cancer was reduced," said lead author Daniel Schauer, MD, associate professor in the University of Cincinnati (UC) Division of General Internal Medicine,
in a press release.

According to a new report from the Centers of Disease Control and Prevention (CDC), overweight- and obesity related cancers account for 40 percent of all cancers in the United States. The CDC says excess weight is associated with increased risk of at least 13 different types of cancer.

UC researchers reviewed the medical data of 22,198 individuals who had bariatric surgery and 66,427 nonsurgical patients between 2005 and 2012 with follow-up through 2014. The data came from large integrated health insurance and health care delivery systems from five study sites operated by Kaiser Permanente in Southern California, Northern California, Oregon, Colorado and Washington.

After a mean follow-up of three and a half years, researchers identified 2,543 cases of cancer; 488 in the surgery group and 2,055 in the nonsurgical group.

It is noted that the study found no significant reductions of cancer risk for men. Researchers say this may be explained by the fact that 80 percent of study participants were women and only they run the risk of developing postmenopausal breast and endometrial cancer, two of the most common cancers related to obesity. For men, prostate and lung cancer are the most common, neither of which, they say, is associated with obesity.

The latest study is made even more significant by the Centers for Disease Control and Prevention’s (CDC) report, “Trends in Incidence of Cancers Associated with Overweight and Obesity,” published online Oct. 3, which shows rates of 12 out of 13 obesity-related cancers increased by 7 percent from 2005 to 2014 while cancers not associated with overweight and obesity fell by 13 percent.

"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," said Dr. Schauer. "The study provides an additional reason to consider bariatric surgery."