Biliary tract cancer

Investigation into the molecular and cellular biology of carcinogenesis continues to elucidate potential mechanisms for the initiation and progression of biliary tract cancer. The potential role of cell cycle regulators, such as Fas ligand, has been examined in the etiology of bile duct carcinoma. In addition, there is evidence for a possible link between chronic inflammation and malignant transformation through the relation between nitric oxide and DNA repair enzymes. Noninvasive imaging modalities, including helical computed tomography scanning, magnetic resonance cholangiopancreatography (MRCP) and positron emission tomography (PET) scanning, are gaining acceptance and may eventually supplant standard methods of evaluation. In addition, innovative tissue-sampling modalities including choledochoscopy are being developed. Several large series, Japanese and Western, continue to report improved 5-year survival rates after aggressive surgical resections of hilar cholangiocarcinoma. Although chemotherapeutic options remain limited in biliary tract carcinoma, radiation therapy may provide a benefit in local control in patients with microscopically positive margins. Photodynamic and multimodality therapy also may become important components of improving palliation for patients with advanced disease.