Comprehensive Gene Panel Analysis of Biliary Tract Cancer Using Next-Generation Sequencing of Endoscopic Transpapillary Brushing/Biopsy/Aspiration Specimens: A Narrative Review.

The undesired prognosis of biliary tract cancer is mainly attributed to the difficulty in detecting cancer lesions, including intraepithelial neoplasia, and other hurdles in procuring sufficient pathological samples by forceps biopsy and brushing, or even their combination. However, the transpapillary approach under endoscopic retrograde cholangiopancreatography (ERCP) is the mainstream approach for the work-up and treatment of biliary tract diseases, especially biliary tract cancers, because the ERCP-guided approach efficiently enables simultaneous biliary drainage for the treatment of cholangitis/jaundice and specimen acquisition for the diagnosis of biliary tract lesions. To improve diagnostic accuracy, several studies have been conducted on the feasibility and efficacy of genomic analysis of endoscopic specimens, namely, brushing samples, forceps biopsy samples, and aspiration samples such as bile with sensitivities ranging from 47 to 100%, with specificities ranging from 69 to 100%. Clinical use of genomic analysis remains heterogeneous due to the panel and next-generation sequencing system. For the efficient and precise treatment of patients with biliary tract cancer, future diagnosis and treatment should be based on molecular and genetic analyses. In this article, we review and summarize the comprehensive gene panel analyses of transpapillary brushing/biopsy/aspiration specimens for biliary tract cancer using next-generation sequencing, promoting effective clinical practice and providing a basis for future studies.