OBJECTIVETo clarify the relationship between the loss of expression of the deleted in pancreatic carcinoma locus 4 (DPC4) proteins and the pathogenesis of biliary tract carcinoma.

METHODS71 primary biliary tract carcinoma (BTCa), including 38 common bile duct (CBD) carcinomas, 18 gallbladder carcinomas, 15 hilar bile ducts (HBD) carcinomas were examined by immunohistochemical staining. In addition, the CBD carcinomas were divided into two groups: tumors with metastasis (M(+) group, 27 cases) and tumors without metastasis (M(-) group, 11 cases).

RESULTSThe frequency of loss of the expression of DPC4 protein was 32.8% in BTCa, 47.3% in CBD carcinoma, 11% in gallbladder carcinoma, 13% in HBD carcinoma. Comparison of the frequency of loss expression of DPC4 was significant statistical difference in CBD carcinoma versus gallbladder carcinoma and HBD carcinoma (P < 0.01). The frequency of loss expression of DPC4 was 48.1% in the M(+) group and 45.4% in the M(-) group.

CONCLUSIONThere are a close relationship between pathogenesis of BTCa and inactivation of DPC4 and different frequencies of DPC4 gene alternation in various locations of the biliary tract, which are not significantly increased with tumor metastasis in BTCa.