Liquid Biopsy in Gastrointestinal Stromal Tumor

Over the past 15 years, gastrointestinal stromal tumors (GISTs) have emerged from a poorly understood neoplasm to a well-defined tumor entity. Starting from 2000, the discovery of gain-of-function mutations involving KIT or PDGFRα (platelet-derived growth factor-α) genes and the development of tyrosine kinase inhibitors (TKIs), such as imatinib, revolutionized dramatically the management of GISTs. Due to the almost continual emergence of new data about biological complexity of GISTs and more sophisticated whole-genome technologies, to date, the role of molecular biology is clinically important to drive therapeutic decision making. The possibility of using liquid biopsy in GISTs was reported for the first time at the 2013 ASCO Annual Meeting. Detection of circulating tumor DNA (ctDNA) offers a wide spectrum of applications in GIST management. CtDNA correlates with the tumor burden, thus, after surgery may indicate the presence of minimal residual disease and patients with high risk of recurrence. In addition, during the clinical treatment, this approach could be used to identify early biomarkers of response and assess variations in whole genome, early identifying the development of secondary resistance.