Biomarkers for Diagnosis, Risk Stratification, and Immunotherapy of Pediatric Solid Tumors

There is a continued need to accurately diagnose, risk stratify, select treatment, and develop immunotherapies for extracranial pediatric solid tumors, and biomarkers are uniquely poised to meet this need. In most pediatric solid tumors, biomarkers are being used to enhance diagnostic accuracy and/or contribute to selection of risk-stratified systemic chemotherapy. Biomarker-selected targeted therapy and biomarker-informed immunotherapy approaches are less common. Liquid biopsy (LB) is emerging as an important prognostic biomarker in pediatric solid tumors. While the field is rapidly evolving with the exploration of novel technologies, challenges remain, including defining gold standard methods for LB in the clinic. In addition, biomarkers are still being explored as direct or indirect immunotherapeutic targets. In this review, we will provide a comprehensive overview of the biomarker landscape for the more common pediatric solid tumors.