Pediatric brain tumors: genetics and clinical outcome.

OBJECT: In this paper the authors' goal was to investigate the genetic characteristics of primary brain tumors in children and determine their influence on clinical outcome.
METHODS: The authors performed high-resolution comparative genomic hybridization studies in 14 low-grade and 12 high-grade brain neoplasms in 26 children who underwent surgery between 2005 and 2007.
RESULTS: Complex comparative genomic hybridization alterations were observed in 2 (14.3%) of the 14 lowgrade lesions and in 8 (66.6%) of the 12 high-grade lesions. High-level amplifications of DNA were detected in 3 cases, namely in a desmoplastic medulloblastoma where a c-Myc amplification was found. Gains of 1q were detected in 2 low-grade and 6 high-grade lesions that were classified as ependymomas, astrocytomas, oligodendrogliomas, oligoastrocytomas, and gangliogliomas. When the authors correlated genetics with outcome, they noted that among the low-grade neoplasms only the 2 patients who presented with complex comparative genomic hybridization alterations had to undergo reoperation because of recurrent disease. The patient with c-Myc amplification died of progressive disease. Gains of 1q were only observed in tumor cases with progressive disease.
CONCLUSIONS: Complex genetic alterations are indicative of a less favorable outcome in low-grade tumors. In these cases, closer follow-up should be pursued. The authors corroborate that c-Myc amplification is a marker of poor prognosis in medulloblastomas. In this study, they were able to verify that a 1q gain correlates with a poor clinical outcome, independent of tumor grade and histological type. The authors propose that it may be considered a common marker of poor prognosis in these neoplasms.