Bariatric Surgery: Half the Risk of Cancer Death

“The best possible evidence on the value of intentional weight loss to reduce cancer risk and mortality.” This is how the Cleveland Clinic’s Steven Nissen describes the release of a new study in JAMA yesterday. These observations come from a matched cohort study of 30,318 persons by Ali Aminian and colleagues. They found a 48 percent reduction in the risk of cancer death linked to bariatric surgery. Furthermore, they found a reduction by a third in the incidence of 13 different types of cancer.

This study adds to the evidence suggesting this possible benefit from bariatric surgery. In an editorial alongside this new study, Anita Courcoulas writes:

“This report by Aminian et al is not the first observational study to demonstrate this association, but it does lend even more support to the finding that people who undergo bariatric surgery may experience a decreased risk of cancer.”

Matched Cohorts

Aminian et al studied 5,053 persons with a BMI of 35 or more who had bariatric surgery. Their control group was 25,265 persons with no surgery. Of course, this is an observational study. So residual confounding will always be a question. But to address this concern, the researchers used a logistic regression model to match the control group to the surgery group.

So the analysis is robust, even though one cannot be certain the benefit of reduced cancer deaths is entirely due to the surgery.

Obesity and Cancer

The link between obesity and many types of cancer is very clear. These include multiple myeloma, breast, endometrial, ovarian, esophageal, gallbladder, colorectal, renal cell, liver, pancreas, and thyroid cancer. Obesity promotes these cancers in multiple ways, through mechanisms we understand with increasing clarity.

So we have trouble with people who promote the idea that obesity is not a real health concern. It’s not that we favor catastrophizing obesity. We don’t. But we do favor being honest about the risks it presents. Even more so, honesty about options for dealing with obesity is important. Needs and choices about this are very personal. What works for one will never work for all. This is a chronic disease, so treatment is all about managing it. Not curing it.

Nevertheless, people do have good options and bariatric surgery, for many people, is clearly one of them. It can help people lead longer, healthier, and often happier lives. Though choosing this option is no small decision, it can be quite an important, even life-changing choice.

Click here for the new study in JAMA, here for the editorial, and here for further reporting.

Half Peeled Lemon, painting by Pieter Claesz / WikiArt

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June 4, 2022