TOPLINE

Metabolic/bariatric surgery (MBS) was associated with a lower risk for obesity-related malignancies, non-obesity-related cancers, solid tumors, and hematologic malignancies than structured dietary counseling in adults with severe obesity.

METHODOLOGY

• Obesity is a key driver of increased risk for cancer and mortality; however, the impact of MBS compared with structured dietary counseling on cancer risk is unclear.
• Researchers used data from an electronic health record-based platform to conduct a retrospective cohort study comparing 90,192 propensity score-matched patients without cancer who underwent MBS (mean age, 42.6 years; 79.8% women; mean BMI, 45.6) or received documented dietary counseling or education (mean age, 44.3 years; 80.1% women; mean BMI, 43.9). Matching incorporated demographics, comorbidities, tobacco and alcohol use, hormone exposure, immunosuppressive therapy, and cancer screening encounters.
• MBS included Roux-en-Y gastric bypass, sleeve gastrectomy, biliopancreatic diversion with duodenal switch, and adjustable gastric banding.
• The primary outcome was incident obesity-related malignancies (breast cancer, colorectal cancer, endometrial cancer, pancreatic cancer, kidney cancer, liver cancer, and esophageal adenocarcinoma). Secondary outcomes were non-obesity-related cancers, solid tumors, and hematologic malignancies.
• Patients were followed from 1 day after the index date (first bariatric procedure or first dietary counseling encounter) until diagnosis of an outcome, death, loss to follow-up, or up to 5 years.

TAKEAWAY

• MBS was associated with a lower risk for obesity-related malignancies than dietary counseling (hazard ratio [HR], 0.775), with reductions observed for breast (HR, 0.856), colorectal (HR, 0.693), endometrial (HR, 0.599), pancreatic (HR, 0.513), and liver and intrahepatic bile duct cancers (HR, 0.601).
• The risk for non-obesity-related malignancies was lower in the MBS group than in the dietary counseling group (HR, 0.784), with a significant reduction in the risk for lung cancer (HR, 0.498).
• MBS was associated with a lower risk for solid tumors (HR, 0.801) and hematologic malignancies (HR, 0.824) than dietary counseling.

IN PRACTICE

“Overall, these findings suggest that metabolic surgery may confer broader cancer risk modification than previously appreciated and support further prospective and mechanistic investigation,” the authors wrote.

SOURCE

The study, led by Wissam Ghusn, MD, Mayo Clinic in Rochester, Minnesota, was published online in Obesity Surgery.

LIMITATIONS

The study had an observational design, relied on administrative codes, and lacked detailed information on tumor stage and procedure subtype. The follow-up period may not have enabled capturing data on cancers with very long latency. Residual immortal time bias could not be fully excluded.

DISCLOSURES

This study did not receive any funding. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.