New molecular biomarkers have potential to transform pediatric cancer | ASCO 2026

Molecular profiling now yields actionable results for a meaningful share of pediatric patients with solid tumors, says Katherine A. Janeway, M.D., senior physician at Dana-Farber/Boston Children's Cancer and Blood Disorders Center and director of Clinical Genomics at Dana-Farber Cancer Institute.

For about 5% to 10% patients, molecular profiling is really transformative, Janeway, a specialist in bone sarcomas, said in an interview ahead of the American Society of Clinical Oncologist annual meeting in Chicago. She is speaking during a session about the progress for new biomarkers and treatments targeting molecular alterations specific to pediatric cancers.

Tumor sequencing has clarified diagnoses in roughly 5% of cases, uncovered hereditary cancer predispositions in approximately 15%, and identified potentially targetable molecular alterations in 30% to 60% of pediatric solid tumor patients. For some patients — particularly those harboring kinase fusions — molecularly targeted therapies have produced dramatic responses where conventional chemotherapy had failed.

Childhood cancers, she pointed out, present molecular profiles that are fundamentally different from adult malignancies. Where adult oncology has long leaned on sequencing for point mutations and short sequence variants, pediatric solid tumors are frequently driven by gene fusions and copy number changes.

Ewing sarcoma, for instance, is a highly aggressive bone cancer in children and adolescents and is defined by a transcription factor fusion, not a kinase mutation. Osteosarcoma is another cancer of the bone that affects adolescents and features a highly complex genome dominated by chromosomal structural variants.

Her ASCO presentation centers on newly identified molecular biomarkers in Ewing sarcoma and osteosarcoma that predict poor outcomes under standard therapy, findings her lab hopes will underpin the first molecularly risk-stratified clinical trial in Ewing sarcoma, a model already proven in neuroblastoma.