Can Bariatric Surgery Decrease the Risk of Obesity-Related Cancers?

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A new study presented at Digestive Disease Week 2023 has shown that just 4% of patients with obesity who underwent bariatric surgery developed obesity-associated cancer in a 10-year follow-up, compared with 8.9% among those who did not have a weight-loss procedure.1 These findings indicate that the significant weight loss resulting from bariatric surgery may have a protective effect against the formation of certain cancers, in addition to its known health advantages.

Vibhu Chittajallu, MD, the study’s lead author and a gastroenterology fellow at Case Western Reserve University and University Hospitals, Cleveland, explained the importance of these findings: “When considering bariatric surgery, most people focus on the weight loss and the accompanying physical and psychological benefits, such as improved blood pressure and diabetes management. This study adds to the growing body of evidence suggesting that the significant weight loss associated with bariatric surgery may also have a protective effect against cancer formation.”

“These results demonstrated that bariatric surgery had a significant impact on lowering the risk of de novo cancers in patients with obesity.”
— Vibhu Chittajallu, MD

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According to the Centers for Disease Control and Prevention, nearly 42% of American adults have obesity, and the rates are continuing to rise. Obesity has been associated with multiple serious illnesses including type 2 diabetes, heart disease, and cancer.

As Dr. Chittajallu explained, the primary modality for significant weight loss and obesity is bariatric surgery, including sleeve gastrectomy, gastric bypass, and gastric band procedures. The benefits of these procedures include improvement in patients’ mental and physical well-being—and now perhaps some protection from the development of cancer.

Study Design

For this study, Dr. Chittajallu and colleagues retrospectively gathered data from the TriNetX database, which contains records of more than 107 million patients from 47 U.S. health-care organizations. The researchers examined the medical records of patients with obesity who had undergone sleeve gastrectomy, gastric bypass, or gastric band procedures and compared them with a similar number of patients who did not have the procedure. The research team also controlled for risk factors that contribute to cancer formation, such as smoking history, alcohol use, heart disease, hormone therapies, and other comorbidities. After propensity score matching, the researchers included 55,789 patients in each cohort.

Significant Weight Loss May Have Cancer-Prevention Benefits

After a 10-year follow-up, 2,206 patients among those who had bariatric surgery developed obesity-associated cancers, compared with 4,960 among those who did not have the procedure. The study found that the group of patients who underwent weight-loss surgery had consistently lower numbers of new cases for almost all types of obesity-related cancer, including breast (501 vs 751), colon (201 vs 360), liver (969 vs 2,198), pancreas (54 vs 86), ovarian (130 vs 214), and thyroid (154 vs 175).


  • Bariatric surgery may significantly reduce the risk of developing obesity-related cancers.
  • Patients who underwent weight-loss surgery had consistently lower numbers of new cases for various types of obesity-associated cancers.

“These results demonstrated that bariatric surgery had a significant impact on lowering the risk of de novo cancers in patients with obesity,” said Dr. Chittajallu. “The findings support the importance of treating obesity with weight-loss surgery to help reduce the societal and economic burden of cancer.”

“We need more research to understand how bariatric surgery affects cancer risk. However, the significant findings from this study suggest it’s an exciting avenue for further study,” he added. According to Dr. Chittajallu, ongoing and future studies will help to better understand the protective effects of significant weight loss on cancer formation, potentially leading to new treatment options and prevention strategies for those at risk of obesity-related cancers. 

DISCLOSURE: Dr. Chittajallu reported no conflicts of interest.


1. Chittajallu V, Mansoor E, Perez J, et al: Bariatric surgery decreases the risk of developing cancer: A multicenter population-based study. Digestive Disease Week 2023. Abstract 443. Presented May 7, 2023.

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