A comprehensive Nordic study tracking over 109,000 bariatric surgeries has identified a significant long-term risk of adenocarcinoma in the excluded stomach following Roux-en-Y gastric bypass. While rare, the incidence of this cancer more than doubles 10 to 44 years post-surgery compared to other bariatric procedures.
Researchers found that gastric bypass patients had an adjusted hazard ratio of 4.0 for developing gastric non-cardia adenocarcinoma in the later period, compared to a hazard ratio of 1.0 within the first nine years. The standardized incidence ratio against the general population also showed a 2.5-fold increase in risk between 10 and 44 years after the procedure.
Furthermore, outcomes for those diagnosed with excluded stomach cancer appeared less favorable after gastric bypass. Gastrectomy was less common, and all-cause mortality was higher, though confidence intervals were wide. These findings highlight the need for long-term vigilance and emphasize the potential diagnostic challenges due to the bypassed anatomy.