Genomic ALK alterations in primary and relapsed neuroblastoma

Background Genomic alterations of the anaplastic lymphoma kinase gene ( ALK ) occur recurrently in neuroblastoma, a pediatric malignancy of the sympathetic nervous system. However, information on their development over time has remained sparse. Methods ALK alterations were assessed in neuroblastomas at diagnosis and/or relapse from a total of 943 patients, covering all stages of disease. Longitudinal information on diagnostic and relapsed samples from individual patients was available in 101 and 102 cases for mutation and amplification status, respectively. Results At diagnosis, ALK point mutations occurred in 10.5% of all cases, with highest frequencies in stage 4 patients