Pancreaticobiliary Maljunction Independently Predicts Early Recurrence after Surgical Resection for Gallbladder Carcinoma without Hepaticojejunostomy: A Propensity-Weighted Cohort Study.

BACKGROUND: Pancreaticobiliary maljunction (PBM) is a recognized congenital risk factor for gallbladder cancer (GBC), but its prognostic significance after GBC diagnosis remains unclear. PATIENTS AND METHODS: This single-center retrospective cohort study included 229 patients with pathologically confirmed GBC treated between 2015 and 2025, comprising 75 with PBM and 154 with non-PBM (NPBM). The primary analysis was predefined in the surgery without hepaticojejunostomy (HJ) group to assess the prognostic association of PBM under a relatively homogeneous surgical strategy, with secondary analyses among all surgically resected patients and palliative/nonsurgical patients. Overlap weighting was used to improve baseline comparability, and survival outcomes were evaluated using complementary Cox regression models. RESULTS: Patients with PBM were younger and less likely to have cholelithiasis than patients with NPBM. PBM tumors more frequently showed high Ki-67 expression and aberrant p53 immunostaining patterns. PBM was associated with worse overall survival (OS) in the palliative/nonsurgical group (hazard ratio [HR] 3.10, 95% confidence interval [CI] 1.57-6.11; P < 0.001). In the surgery without HJ group, PBM was independently associated with worse recurrence-free survival (RFS) in the primary analysis (adjusted HR 2.10, 95% CI 1.13-3.89; P = 0.019). A similar trend was observed for OS, although it did not reach statistical significance. Exploratory subgroup analyses revealed a significant interaction between PBM and HJ. CONCLUSIONS: PBM was associated with poorer RFS after surgery without HJ and worse OS in the palliative/nonsurgical group. These findings underscore the need for intensified surveillance in PBM-associated GBC and suggest that the role of concurrent biliary reconstruction warrants prospective evaluation.