Relationship between pancreaticobiliary maljunction and gallbladder carcinoma: a meta-analysis

BACKGROUND: Reports on the relationship between pancreaticobiliary maljunction (PBM) and gallbladder carcinoma (GBC) are conflicting. The frequency of PBM in GBC patients and the clinical features of GBC patients with PBM vary in different studies. DATA SOURCES: English-language articles describing the association between PBM and GBC were searched in the PubMed and Web of Science databases. Nine case-control studies fulfilled the inclusion criteria and addressed the relevant clinical questions of this analysis. Data were extracted independently by two reviewers using a predefined spreadsheet. RESULTS: The incidence of PBM was higher in GBC patients than in controls (10.60% vs 1.76%, OR: 7.41, 95% CI: 5.03 to 10.87, P<0.00001). The proportion of female patients with PBM was 1.96-fold higher than in GBC patients without PBM (80.5% vs 62.9%, OR: 1.96, 95% CI: 1.09 to 3.52, P=0.12). GBC patients with PBM were 10 years younger than those without PBM (SMD: -9.90, 95% CI: -11.70 to -8.10, P<0.00001). And a difference in the incidence of associated gallstone was found between GBC patients with and without PBM (10.8% vs 54.3% OR: 0.09, 95% CI: 0.05 to 0.17, P<0.00001). Among the GBC patients with PBM, associated congenital dilatation of the common bile duct was present with a higher incidence ranging from 52.2% to 85.7%, and 70.0%-85.7% of them belonged to the P-C type of PBM (the main pancreatic duct enters the common bile duct). No substantial heterogeneity was found and no evidence of publication bias was observed.CONCLUSIONS: PBM is a high-risk factor for developing GBC, especially the P-C type of PBM without congenital dilatation of the common bile duct. To prevent GBC, laparoscopic cholecystectomy is highly recommended for PBM patients without congenital dilatation of the common bile duct, especially relatively young female patients without gallstones.