Bariatric Surgery May Reduce Risk of Obesity-Related Cancers by More Than Half

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Researchers have found that patients who are obese and undergo bariatric surgery may have a greater than 50% decreased incidence rate of obesity-related cancer compared with patients who did not have the weight-loss procedure, according to new findings presented by Chittajalu et al at Digestive Disease Week 2023.


"The primary benefit [patients] consider when they think about bariatric surgery is weight loss and the accompanying physical and psychological benefits, such as improved blood pressure and diabetes,” explained lead study author Vibhu Chittajallu, MD, a gastroenterology fellow at the Case Western Reserve University School of Medicine, Cleveland Clinic, and University Hospitals Cleveland Medical Center. “This study adds to the building evidence that the significant weight loss associated with bariatric surgery may have a protective effect against cancer formation as well,” he added.

Study Methods and Results

In the new study, the researchers compared the data of more than 55,700 patients with obesity who underwent bariatric surgery with 55,700 patients who did not undergo bariatric surgery. The researchers included patients who had sleeve gastrectomy, gastric bypass, or gastric band procedures and further controlled for risk factors that may play a role in cancer formation—such as smoking history, alcohol use, cardiovascular disease, hormone therapy, and other comorbidities.

After a follow-up of 10 years, the researchers discovered that just 4% (n = 2,206/55,700) of the patients who underwent bariatric surgery developed obesity-associated cancers compared with 8.9% (n = 4,960/55,700) among those who did not undergo the surgery.

Additionally, the patients who underwent bariatric surgery had consistently lower numbers of new cases for virtually all types of obesity-related cancer compared with the patients who did not undergo the weight-loss procedure—including breast cancer (501 vs 751), colorectal cancer (201 vs 360), hepatic cancer (969 vs 2,198), pancreatic cancer (54 vs 86), ovarian cancer (130 vs 214), and thyroid cancer (154 vs 175).


“We need more research to understand how bariatric surgery affects cancer risk, but the significant findings from this study suggest it’s an exciting avenue for further study,” concluded Dr. Chittajallu.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.