Published online Sep 15, 2021. doi: 10.4251/wjgo.v13.i9.1073
Peer-review started: February 16, 2021
First decision: May 3, 2021
Revised: June 14, 2021
Accepted: August 11, 2021
Article in press: August 11, 2021
Published online: September 15, 2021
Processing time: 205 Days and 20.5 Hours
Biliary tract cancer, comprising gallbladder cancer, cholangiocarcinoma and ampullary cancer, represents a more uncommon entity outside high-endemic areas, though global incidence is rising. The majority of patients present at a late stage, and 5-year survival remains poor. Advanced stage disease is incurable, and though palliative chemotherapy has been shown to improve survival, further diagnostic and therapeutic options are required in order to improve patient outcomes. Although certain subtypes of biliary tract cancer are relatively rich in targetable mutations, attaining tumour tissue for histological diagnosis and treatment monitoring is challenging due to locoregional anatomical constraints and patient fitness. Liquid biopsies offer a safe and convenient alternative to invasive procedures and have great potential as diagnostic, predictive and prognostic biomarkers. In this review, the current standard of care for patients with biliary tract cancer, future treatment horizons and the possible utility of liquid biopsies within a variety of contexts will be discussed. Circulating tumour DNA, circulating microRNA and circulating tumour cells are discussed with an overview of their potential applications in management of biliary tract cancer. A summary is also provided of currently recruiting clinical trials incorporating liquid biopsies within biliary tract cancer research.
Core Tip: Liquid biopsies represent an enticing prospect in biliary tract cancer. In this review, we discuss the rationale, methods and utility of liquid biopsies for predictive and prognostic purposes, including circulating tumour DNA, circulating tumour cells and circulating microRNA. A summary is provided of current trials utilising liquid biopsies in biliary tract cancer.