Does Weight Loss Surgery Reduce the Risk for Cancer?

Risks of Obesity

Obesity increases the risk for several illnesses. Type 2 diabetes, high blood pressure, high cholesterol, obstructive sleep apnea, liver disease, depression and many other health problems are more common in obese people than in normal weight people. It is well known that weight loss surgery, also called bariatric surgery, is effective for more than only weight loss. Weight loss operations – gastric band, gastric bypass and sleeve gastrectomy – can improve, and even cure, diseases that go along with obesity.

Risk for Cancer in Obese People

What about cancer? Does obesity have any impact on the risk for getting cancer? There have been various studies on this topic. A recently published paper in the British Medical Journal(1) has analysed the linkage between obesity and cancer in detail. Many questions remain unanswered, but the bottom line is quite clear. Obesity increases the risk of cancer. The researchers found strong evidence for the association between obesity and eleven types of cancer: oesophageal adenocarcinoma (cancer of the food-pipe or gullet), multiple myeloma (a type of blood cancer), and cancers of the gastric cardia (the upper part of the stomach), colon and rectum (the large bowel), pancreas gland, biliary tract, breast, endometrium, ovary and kidney. The researchers suggest that those at higher risk for cancer could be targeted for personalized prevention strategies.

Weight Loss Surgery and Cancer Risk Reduction

Can weight loss surgery reduce the risk for cancer in obese people? There are few studies that look at this problem. It is not entirely clear whether the risk is reduced for all cancers, and whether all obese people can benefit. Women seems to benefit more than men. In fact, one large study has shown that the risk for cancer is reduced only in women and not in men.(2) Other studies may shown reduced cancer risk in both men and women, but the benefit remains greater in women.(3) Much work remains to be done in this area. But, the message is fairly clear: obesity increases the risk for cancer. Weight loss surgery has many benefits, and reduction of cancer risk is one of these many benefits.



  1. Kyrgiou M, Kalliala I, Markozannes G, Gunter MJ, Paraskevaidis E, Gabra H, et al. Adiposity and Cancer at Major Anatomical Sites: Umbrella Review of the Literature. Br Med J (Clin Res Ed). 2017;356.
  2. Sjostrom L, Gummesson A, Sjostrom CD, Narbro K, Peltonen M, Wedel H, et al. Effects of Bariatric Surgery on Cancer Incidence in Obese Patients in Sweden (Swedish Obese Subjects Study): A Prospective, Controlled Intervention Trial. The Lancet Oncology. 2009;10(7):653-62.
  3. Maestro A, Rigla M, Caixas A. Does Bariatric Surgery Reduce Cancer Risk? A Review of the Literature. Endocrinology & Nutrition. 2015;62(3):138-43.