Liquid biopsies, particularly those involving cell-free DNA (cfDNA), are a promising non-invasive, cost effective method of monitoring disease in cancer patients with solid tumors and are being increasingly employed in various adult malignancies to diagnose disease, monitor tumor response, detect relapse and learn more about tumor biology. The utility of liquid biopsies which may include isolation and analysis of tumor derived material such as DNA, RNA, intact cells, proteins, or exosomes from blood or other bodily fluids in pediatric solid tumors has not been established. In this study, we propose to prospectively collect serial blood samples at baseline, during therapy, end of therapy, relapse, and during follow up from patients ≥ 6 months of age with newly diagnosed or relapsed/refractory various pediatric non-CNS malignant solid tumors to determine the feasibility of detecting various tumor-derived material, including exosomes, circulating tumor cells, and circulating tumor nucleic acid (ctDNA and ctRNA). The timing of blood sample collection will be during a routine lab draw around the time of a disease evaluation. The ctDNA and ctRNA as well as DNA and RNA extracted from tumor-derived exosomes will be quantified at each time point and the findings will be correlated with conventional methods for disease evaluation (e.g., imaging studies, histologic tumor response, or serum tumor markers) and outcome (overall survival and event-free survival).
