Bariatric surgery and risk of gastrointestinal and hormone-sensitive cancers in patients with metabolic-associated steatotic liver disease and obesity: A multicenter matched cohort study.

10547 Background: Metabolic-associated steatotic liver disease (MASLD) is strongly associated with an increased risk of hormone-sensitive and gastrointestinal (GI) malignancies due to obesity-related pro-inflammatory states and altered hormone metabolism. Bariatric surgery (BS) has shown promise in ameliorating MASLD and obesity-related comorbidities; however, data on its potential to reduce cancer risk in this population remain scarce. Hence, we aimed to assess the impact of BS on the risk of hormone-sensitive and GI cancers in patients with MASLD and obesity using a multicenter, matched cohort design. Methods: We conducted a retrospective cohort study utilizing the TriNetX. Patients who underwent BS (including Roux-en-Y Gastric Bypass and Sleeve Gastrectomy) were included in the BS cohort and matched controls who are standard of care without a history of BS. We performed 1:1 propensity score matching (PSM) to reduce confounder factors, including demographics, comorbidities, BMI, nicotine dependence, and family history of malignancy. A 1-year lag time was applied to minimize protopathic bias. Cox proportional hazard analysis was performed to calculate hazard ratios (HR) for overall cancer risk, hormone-sensitive cancers (endometrial, breast, prostate, kidney, and ovarian), and GI cancers (colon, rectal, pancreatic, biliary, and hepatocellular). Results: A total of 9848 patients with MASLD underwent BS, while 183837 MASLD patients had no history of BS. After PSM, 9791 patients were included in each cohort. The mean follow-up was 4.8 years for BS and 5.1 years for controls. BS was associated with a significantly lower overall cancer risk (HR: 0.72 (0.65-0.80)). Among hormone-sensitive cancers, BS patients demonstrated reduced risks of endometrial (HR 0.50) and breast cancer (HR 0.62), with no significant differences for prostate, ovarian, lung, or thyroid cancer. A lower risk of kidney cancer was noted (HR 0.91). For GI malignancies, BS patients had a reduced risk of HCC (HR 0.32), malignant neoplasms of the cholangiocarcinoma (HR 0.29), pancreatic cancer (HR 0.18), and colon cancer (HR 0.53). No differences were observed for esophageal or gastric cancers. Conclusions: In this large multicenter analysis, BS was associated with a significantly lower risk of hormone-sensitive and GI cancers in patients with MASLD and obesity. These findings suggest that weight loss and improved metabolic profiles following surgery may mitigate the pro-inflammatory and pro-neoplastic effects of obesity and MASLD. Further research is needed to explore BS's underlying mechanisms and long-term cancer prevention benefits.