Carcinogenesis in the biliary system associated with APDJ.

Anomalous pancreaticobiliary ductal junction (APDJ) is a rare congenital anomaly which is considered to be an etiological factor in the development of carcinoma of the biliary tract. It is generally accepted that pancreatic juice reflux into the biliary tract due to APDJ is one of the etiologies of biliary tract cancers. Refluxing pancreatic juice results in changes of bile and induces chronic inflammation and increased cellular proliferation, leading to epithelial hyperplasia, metaplasia, and carcinoma of the biliary tract. K-ras mutations are more prevalent in the carcinomas of biliary tract associated with APDJ compared with those without APDJ. There is no difference in the overexpression of p53 between biliary tract carcinomas associated with APDJ and those unassociated with APDJ. Further studies are needed to evaluate the role of cytokines and growth factors in carcinogenesis of the biliary system associated with APDJ.