Emerging role of circulating cell-free RNA as a non-invasive biomarker for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a severe neoplastic disease associated with high morbidity and mortality rates. HCC is often detected at advanced stages leading to ineffective curative treatments. Recently, liquid biopsy has emerged as a non-invasive method to identify highly specific HCC biomarkers in bodily fluids such as blood, serum, urine, and saliva. Circulating cell-free nucleic acids (cfNAs), particularly cell-free DNA (cfDNA) and cell-free RNA (cfRNA), have become promising candidates for biomarkers in liquid biopsy applications. While cfDNA presented significant challenges, researchers have turned their attention to cfRNA, which can be efficiently identified through various methods and is considered a potential biomarker for cancer diagnosis and prognosis. This review primarily focuses on studies related to detecting various cfRNA in body fluids as biomarkers. The aim is to provide a summary of available information to assist researchers in their investigations and the development of new diagnostic and prognostic tools.