Copy number gain of MYCN gene is a recurrent genetic aberration and favorable prognostic factor in Chinese pediatric neuroblastoma patients

In this study, we analyzed MYCN gene and chromosome 2 aneusomy by using fluorescence in situ hybridization (FISH) method in a total of 220 patients with NBL, GNBL and GN cases. Kaplan-Meier curves were generated by using SPSS 12.0 software.Of 220 patients, 178 (81.0%) were NBLs, 32 (14.5%) were GNBLs and 10 (4.5%) were GNs. MYCN gain is a recurrent genetic aberration of neuroblastic tumors (71.8%, 158/220), which was found in 129 NBLs (58.6%, 129/220), 25 GNBLs (11.4%, 25/220) and 4 GN cases (1.8%, 4/220). However, MYCN amplification was only present in 24 NBL tumors (13.5%, 24/178) and 1 GNBL case (3.1%, 1/32). Kaplan-Meier survival analysis indicated that MYCN amplification is significantly correlated with decreased overall survival in NBLs (P=0.017). Furthermore, a better prognosis trend was observed in patients with MYCN gain tumors compared with those with MYCN gene normal copy number tumors and MYCN amplification tumors (P=0.012).In summary, the frequency of MYCN amplification in NBLs is high and is rarely observed in GNBLs and GNs, which suggest MYCN plays an important role in neuroblastic tumors differentiation. MYCN gain appeared to define a subgroup of NBLs with much better outcome and classification of MYCN gene copy number alteration as three groups (amplification, gain and normal) can provide a powerful prognostic indicator in NBLs.The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6417541528559124 webcitePeripheral neuroblastic tumors (NTs) including neuroblastoma(NBL), ganglioneuroblastoma(GNBL), and ganglioneuroma(GN) comprise one of the most common groups of neoplastic disease in infants and children. NBL and GNBL are considered malignant. In contrast, GNs are considered as benign tumors. In histology, NBL, GNBL, and GN can be conceptualized as three maturational manifestations of a common neoplasm [1].Amplification of MYCN oncogene is an established marker indicating aggressive tumor progression o