Liquid biopsy in liver cancer.

Liver cancer has become the second cause of cancer-related death worldwide. Most patients are still diagnosed at intermediate or advanced stage, where potentially curative treatment options are not recommended. Unlike other solid tumors, there are no validated oncogenic addiction loops and the only systemic agent to improve survival in advanced disease is sorafenib. All phase 3 clinical trials testing molecular therapies after sorafenib have been negative, none of which selected patients based on predictive biomarkers of response. Theoretically, analysis of circulating cancer byproducts (e.g., circulating tumor cells, cell-free nucleic acids), namely "liquid biopsy," could provide easy access to molecular tumor information, improve patients' stratification and allow to assess tumor dynamics over time. Recent technical developments and preliminary data from other malignancies indicate that liquid biopsy might have a role in the future management of cancer patients.