Molecular profiling of biliary tract cancer: a target rich disease

Abstract

Biliary tract cancers (BTCs) are relatively uncommon orphan tumors that have an aggressive disease course and a poor clinical outcome. Surgery is the only curative treatment, but most patients present with advanced disease and therefore have a limited survival. Gemcitabine and cisplatin based chemotherapy has been the only widely accepted standard systemic therapy regimen in these patients but these tumors can be chemoresistant, further complicating their management. In recent times, there has been considerable research in the genetics of BTC and with the advent of new, advanced technologies like next-generation sequencing (NGS) we are achieving a greater understanding of its disease biology. With the help of NGS, we have now been able to identify actionable mutations such as in the isocitrate dehydrogenase 1 (IDH1), FGFR2, BRAF and HER2/neu genes for targeted therapeutics and correlate the genetic variations with distinct clinical prognoses. This recent genetic information has the potential to make precision medicine a part of routine clinical practice for the management of BTC patients.

Keywords: ARID1A; FGFR2; Next-generation sequencing (NGS); biliary tract cancers (BTCs); isocitrate dehydrogenase 1 or 2 (IDH1/2); overall survival; targeted therapy.

Figure 1

The figure depicts the molecular spectrum of BTC, based on the location of the tumor. Additionally the prevalence of these mutations along with possible targeted treatment modalities has also been outlined. BTC, biliary tract cancer; IHCCA, intrahepatic cholangiocarcinoma; EHCCA, extrahepatic cholangiocarcinoma; GBC, gallbladder cancer; IDH1/2, isocitrate dehydrogenase 1 or 2.