Bariatric Surgery and the Risk of Cancer

Cancer is one of the risks of obesity that many people do not appreciate. Diabetes and heart disease have links to obesity that many people understand. But cancer as a complication of obesity has not made the charts. Nonetheless, obesity clearly raises the risks of 13 different kinds of cancer. A new study in Gastroenterology confirms that bariatric surgery can reduce cancer risk. In fact, it seems to provide this benefit even in patients with severe obesity and liver disease.

A Retrospective Cohort Study in NAFLD

This study examined outcomes for 98,090 patients between the ages of 18 and 64 years. These were patients with severe obesity and non-alcoholic fatty liver disease (NAFLD). Of those patients, 33,435 received bariatric surgery. For those who did, the risk of any cancer went down by 18 percent.

What’s more, the risk reductions for specific cancers were in types of cancer that obesity causes. In this study, it was colorectal, pancreatic, endometrial, thyroid, and liver cancer, as well as multiple myeloma. for some of these cancers, the reduction was impressive. Liver and pancreatic cancer risk went down by half. Multiple myeloma went down by two thirds.

Confirming Observations in Broader Populations

These findings are the first in patients with NAFLD and severe obesity. These are patients with a particular risk for cancer because of the link between NAFLD and liver cancer. Especially in patients with cirrhosis, researchers found a significant benefit. Prior research has shown that bariatric surgery reduces the risk of cancer and cancer mortality in the general population of patients receiving this treatment.

A Compelling Reason to Treat

Yet anecdotally, we find that some gastroenterologists who treat NAFLD are dismissive of bariatric surgery for these patients. This attitude often goes with a view of obesity as a problem of behavior, not physiology.

So we hope this research provides one more bit of evidence to overcome a pervasive bias that gets in the way of effective obesity treatment. Bariatric surgery cuts the risk of heart disease, puts diabetes into remission, and prevents cancer. There’s no rational excuse for telling patients to go it alone with nothing but self-care.

Click here for the study in Gastroenterology and here for further perspective from yet another new study in PLOS One.

Still Life, Cancers; painting by Pyotr Konchalovsky / WikiArt

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March 29, 2021