MYCN Gene Copy Number Status Detected by FISH Method and Its Correlation with Outcome and Clinicopathological Variables in Childhood Neuroblastoma

Neuroblastoma is the most common extracranial solid tumor in children. MYCN gene amplification (MNA) is an independent prognostic factor for rapid tumor progression and poor prognosis, regardless of age and clinical stage. Gain of the MYCN gene locus on the short arm of chromosome 2 can also be found in neuroblastoma. In this retrospective descriptive analysis of genetic alterations in neuroblastoma tumor samples, both before and after standard chemotherapy, we examined the MYCN gene copy number status in 20 neuroblastic tumor samples using the fluorescence in situ hybridization (FISH) method. We also evaluated its relationship with clinical variables and tumor maturation after standard chemotherapy treatment. Additionally, we compared disease outcomes among different MYCN copy number categories. Among the tumor samples, four (25%) exhibited increased MYCN copy numbers, 20% showed MYCN amplification, and 5% displayed MYCN gain. We observed decreased survival rates in advanced stages of neuroblastoma. Furthermore, in male patients, we noted an association between increased MYCN copy number and metastatic tumors. We found that increased MYCN copy number is moderately associated with an immature phenotype and correlated with lower event-free survival. However, we did not detect a statistically significant difference.