c-myc expression in medulloblastoma and its prognostic value

To identify prognostic factors in medulloblastoma, a common malignant brain tumor of childhood, expression of the oncogene c-myc was examined at the m RNA level by in situ hybridization. c-myc mRNA expression was observed in 3 0 of 72 tumors (42%), The c-myc gene copy number was determined by quantita tive PCR from genomic DNA of paraffin-embedded tumors. c-myc gene amplifica tion was present in 5 of 62 cases (8.3%), Therefore, c-myc amplification wa s obviously not the cause of c-myc mRNA expression in most samples, Kaplan- Meier estimation revealed a significant correlation between c-myc mRNA expr ession and survival (total mean follow-up 4.6 +/- 3.6 years, log-rank p = 0 .02), Multivariate logistic regression analysis including sex, age, histolo gical type, degree of surgical resection and expression of synaptophysin, G FAP and c-myc, was carried out on 54 patients who received both radiotherap y and chemotherapy. The analysis identified expression of c-myc as an indep endent predictive factor of death from disease. (C) 2000 Wiley-Liss, Inc.