Long-Term Cancer Outcomes Following Bariatric Surgery: A Comparative Analysis of Surgical Procedures

Background/Objectives: Metabolic and bariatric surgery (MBS) is known to reduce cancer risk. However, the association between specific bariatric procedures and cancer incidence is not well-studied. This study examined the association between four different MBS procedures and cancer incidence. Methods: Bariatric surgery registry data were linked with statewide cancer registry data from 1979 to 2018. The study included 27,092 adult subjects (aged ≥ 18 years old at surgery) who underwent MBS (BMI ≥ 30 kg/m² at surgery) from 1979 to 2017. Cancer records were linked to MBS patient records, resulting in 1547 cancer cases. Cox proportional hazards regression was used to examine the association between MBS procedure types and cancer incidence. Results: Of all patients, 75% underwent Roux-en-Y gastric bypass (RYGB), 9% adjustable gastric banding (AGB), 10% sleeve gastrectomy (SG), and 6% duodenal switch (BPD-DS). The overall cancer incidence during the follow-up period was 6.4% for RYGB, 4.6% for AGB, 1.6% for SG, and 5.9% for BPD-DS. The mean follow-up duration from surgery to cancer incidence or censoring was 167 months (standard deviation = 121 months). Compared to RYGB, patients who underwent AGB (Hazard Ratio [HR] = 1.26, p = 0.03) and BPD-DS (HR = 1.91, p < 0.01) had a significantly higher hazard of developing cancer, while SG (HR = 1.17, p = 0.33) showed no significant difference. Conclusions: These findings suggest that AGB and BPD-DS may be associated with higher cancer risks compared to RYGB. Additional large population studies are needed to better understand the long-term cancer risks and mechanisms associated with different MBS types.