Genome-Informed Targeted Therapy for Osteosarcoma.

Osteosarcoma (OS) is a highly aggressive cancer for which treatment has remained essentially unchanged for over 30 years. OS is characterized by widespread and recurrent somatic copy-number alterations (SCNAs) and structural rearrangements. In contrast, few recurrent point mutations in protein-coding genes have been identified, suggesting that genes within SCNAs are key oncogenic drivers in this disease. SCNAs and structural rearrangements are highly heterogeneous across OS cases, suggesting the need for a genome-informed approach to targeted therapy. To identify patient-specific candidate drivers, we used a simple heuristic based on degree and rank order of copy number amplification (identified by Whole Genome Sequencing) and changes in gene expression as identified by RNAseq. Using patient-derived tumor xenografts, we demonstrate that targeting of patient-specific somatic copy number alterations leads to significant decrease in tumor burden, providing a roadmap for genome-informed treatment of OS.