Frequency of the ALK gene and its prognostic value in neuroblastoma by FISH

Introduction The anaplastic lymphoma kinase (ALK) gene has been identified as a major neuroblastoma (NB) predisposition gene. Furthermore, there are controversies on the correlation between ALK gene aberration and clinical outcome in neuroblastoma (NBL). Materials and methods We evaluated N-MYC/ALK gene copy number by fluorescence in situ hybridization and analyzed 32 bone marrow samples infiltrated by NB and analyzed their association with the clinical outcome of the patients. Results Although an increase in ALK gene aberration is a recurrent genetic abnormality of NB (50%, 16/32), ALK amplification was only present in one NB (3.2%, 1/32). In addition, ALK positivity also significantly correlates with N-MYC gene copy number (P 0.000). Kaplan–Meier survival analysis indicated that the N-MYC/ALK aberration is correlated with decreased overall survival (OS) in NB. A better prognosis was observed in patients who were negative for N-MYC/ALK normal compared with those who were positive for N-MYC/ALK aberration tumors. Furthermore, ALK aberrations were significantly correlated with inferior survival in NB (P 0.000). Conclusion ALK aberrations in NB were correlated with advanced tumor types and an increase in both N-MYC/ ALK gene aberrations. ALK aberrations predict an inferior prognosis, which can be used as a prognostic factor in NB in clinical practice.