Liquid biopsy in gallbladder carcinoma: Current evidence and future prospective

Although there have been significant advances in the early detection and treatment of gallbladder cancer (GBC), it is still considered a leading cause of morbidity and mortality. Molecular profiling of tumors is generally performed using samples obtained during surgery or biopsy. However, tissue genotyping has its limitations as it only provides a single snapshot and is susceptible to spatial selection bias due to the tumor heterogeneity. Over the past decade, there has been a remarkable transition from invasive diagnostic methods to non-invasive alternatives, including liquid biopsy, for cancer diagnosis and monitoring. Liquid biopsies have ushered in a new era in clinical oncology, enabling convenient tumor sampling, continuous monitoring through repeated analysis, development of personalized treatment regimens, and assessment of therapy resistance. While peripheral blood is the primary medium for these biopsies, other biological fluids, including urine, saliva, and bile, also serve as valuable sources of information. Currently, the focus of blood-based biopsy analyses is on four main sources of biomarkers for cancer detection and stratification: circulating tumor DNA (ctDNA) or circulating free DNA (cfDNA), circulating tumor cells (CTCs), and extracellular vesicle (EVs). There are over 300 clinical trials either ongoing or actively recruiting participants to investigate the diagnostic and prognostic applications of ctDNA/cfDNA in the context of cancer. This review outlines the current standard of care for individuals with GBC, anticipates future treatment developments, and evaluates the potential applications of liquid biopsies in various clinical contexts. The review addresses ctDNA/cfDNA, CTC, and circulating microRNA and highlights their prospective roles in management of GBC.