Biliary tract carcinoma: clinical perspectives on molecular targeting strategies for therapeutic options.

Biliary tract carcinoma (BTC) is a lethal malignancy. This lethality is essentially attributed to both slow carcinogenesis occurring under complex pathological circumstances and to the asymptomatic growth of BTC infiltrating the surrounding structures by varying routes. The disease is therefore usually detected at an advanced stage with a high frequency of distant organ metastasis. To date, conventional chemotherapy and radiation therapy have been notably ineffective against BTC. For an improved treatment outcome of BTC and prolonged survival, there is now a real and urgent need to focus on developing novel and potent therapeutic strategies aimed at exploiting select molecular targets associated with tumor proliferation, invasion, and/or metastasis that would impact in a significant way on clinical outcome. The outcomes of recent studies, by the analysis of BTC cells, BTC animal models, and clinical specimens of BTC patients, have revealed, in detail, the molecular mechanism of carcinogenesis and tumor progression of BTC, and these studies have exploited select molecular targets that could significantly impact the clinical outcome. In the near future, the development of new molecular targeting drugs with potent efficacy against BTC, and the performance of randomized clinical trials of these drugs are urgent and essential for the treatment of patients with BTC.