Genomic Profiling of a Large Set of Diverse Pediatric Cancers Identifies Known and Novel Mutations across Tumor Spectra.

Pediatric cancers are generally characterized by low mutational burden and few recurrently mutated genes. Recent studies suggest that genomic alterations may help guide treatment decisions and clinical trial selection. Here, we describe genomic profiles from 1,215 pediatric tumors representing sarcomas, extracranial embryonal tumors, brain tumors, hematologic malignancies, carcinomas, and gonadal tumors. Comparable published datasets identified similar frequencies of clinically relevant alterations, validating this dataset as biologically relevant. We identified novel ALK fusions in a neuroblastoma (BEND5-ALK) and an astrocytoma (PPP1CB-ALK), novel BRAF fusions in an astrocytoma (BCAS1-BRAF) and a ganglioglioma (TMEM106B-BRAF), and a novel PAX3-GLI2 fusion in a rhabdomyosarcoma. Previously characterized ALK, NTRK1, and PAX3 fusions were observed in unexpected malignancies, challenging the "disease-specific" alterations paradigm. Finally, we identified recurrent variants of unknown significance in MLL3 and PRSS1 predicted to have functional impact. Data from these 1,215 tumors are publicly available for discovery and validation. Cancer Res; 77(2); 509-19. ©2017 AACR.

Activity of c-Met/ALK Inhibitor Crizotinib and Multi-Kinase VEGF Inhibitor Pazopanib in Metastatic Gastrointestinal Neuroectodermal Tumor Harboring EWSR1-CREB1 Fusion.

Malignant gastrointestinal neuroectodermal tumor (GNET) is an aggressive rare tumor, primarily occurring in young adults with frequent local-regional metastases and recurrence after local control. The tumor is characterized by the presence of EWSR1-ATF1 or EWSR1-CREB1 and immunohistochemical positivity for S-100 protein without melanocytic marker positivity. Due to poor responses to standard sarcoma regimens, GNET has a poor prognosis, and development of effective systemic therapy is desperately needed to treat these patients. Herein, we present a patient with a small bowel GNET who experienced recurrent hepatic and skeletal metastases after a primary resection. Comprehensive genomic profiling (CGP) in the course of clinical care with DNA and RNA sequencing demonstrated the presence of an exon 7 to exon 6 EWSR1-CREB1 fusion in the context of a diploid genome with no other genomic alterations. In a clinical trial, the patient received a combination of 250 mg crizotinib with 600 mg pazopanib quaque die and achieved partial response and durable clinical benefit for over 2.8 years, and with minimal toxicity from therapy. Using a CGP database of over 50,000 samples, we identified 11 additional cases that harbor EWSR1-CREB1 and report clinicopathologic characteristics, as these patients may also benefit from such a regimen.