Changes of serum pepsinogen level and ABC classification after bariatric surgery.

BACKGROUND: Very few studies have explored the changes of serum pepsinogen after bariatric surgery and no research has evaluated the feasibility of ABC classification to predict gastric cancer risk after bariatric surgery. METHODS: We enrolled 94 obese subjects that received bariatric surgery, including 41 sleeve gastrectomy (SG) and 53 Roux-en-Y gastric bypass (RYGB). The serum pepsinogen I (PGI), pepsinogen II (PGII), PGI/II ratio and seropositivity of Helicobacter pylori ( H. pylori ) were measured before and one year after surgery. Patients were classified according to ABC classification and post-operative change was evaluated. RESULTS: Preoperatively, four (4.2%) patients were classified into high risk group (classification C and D) for gastric cancer. Significant reduction of PGI, PGII and decrease of PGI/II ratio were noted after bariatric surgery. H. pylori seropositive patients had a greater postoperative change of PGI (-38.6µg/L vs -22.1µg/L, p=0.003) and PGII (-8.0µg/L vs -2.5µg/L, p <0.001) but a less postoperative change of PGI/II ratio (-0.6 vs -2.1, p =0.04) than H. pylori seronegative patients. One year after surgery, the portion of high risk group of ABC classification for gastric cancer increased markedly from 4.2% to 23.7%. CONCLUSION: Both of SG and RYGB resulted in significant reduction of serum PGI and PGII after bariatric surgery, and significantly influenced the ABC classification. The application of ABC classification for gastric cancer screening was limited after bariatric surgery.