Application and Relevance of Organoid/Tumoroid Models in the Context of Pediatric Solid Tumors

Pediatric cancer is the main disease-related cause of death among children. Solid tumors comprise about 60% of all pediatric cancer cases and the current treatment strategy consists of a combination of surgery, chemotherapy, and radiotherapy. The recent NGS-based technologies provided important insights into the molecular biology underpinning pediatric tumors. However, the rarity of these tumors along with the lack of adequate preclinical models impairs the translation of this knowledge into new therapeutic options. Patient-derived organoid (PDO) cultures arise as powerful preclinical tools, to not only study the biology of pediatric tumors but also as a platform for drug testing. Within pediatric cancer, there are studies describing PDOs in retinoblastoma, neuroblastoma, sarcomas, neuroblastoma, kidney tumors, hepatoblastoma, and brain tumors. PDO cultures are able to recapitulate their matching primary tumors at histologic, genomic and transcriptomic levels. Moreover, PDOs are amenable to genetic editing using CRISPR/Cas9 techniques. PDOs retain patient-specific drug sensitivities, which makes them a suitable preclinical model for drug testing. The introduction of PDOs in different stages of drug development could contribute to speeding up this process. Further studies focused on increasing the availability and diversity of PDOs biobanks and the standardization of PDO protocols are required for the full integration of these models in pediatric cancer care.