The prognostic roles of and correlation between ALK and MYCN protein expression in neuroblastoma

Aims To investigate the relations between anaplastic lymphoma kinase ( ALK ) and v-myc myelocytomatosis viral related oncogene neuroblastoma derived homolog ( MYCN ) protein expression and their prognostic roles in neuroblastoma tumours. Methods Sixty-one neuroblastoma tumours obtained at diagnosis were stained with anti- MYCN and anti- ALK antibodies by immunohistochemical staining. The correlations between protein expression of MYCN , ALK and clinicopathological and biological variables of neuroblastoma tumours were analysed. Results High expression of ALK protein could be detected in 25 (41%) and high expression of MYCN protein could be detected in 24 (39.3%) of the 61 neuroblastoma tumours, respectively. The majority of neuroblastoma tumours with evident of ALK or MYCN protein high expression exhibited undifferentiated or poorly differentiated histology (30/35, 85.7%). ALK or MYCN protein high expression in neuroblastoma tumours was associated with adverse clinical prognostic factors and ALK protein high expression was significantly associated with MYCN protein high expression. In addition, either ALK or MYCN protein high expression in neuroblastoma tumours was the independent adverse prognostic factor and also predicted worse survival outcomes for neuroblastoma patients with MYCN non-amplified status or non-high-risk Children’s Oncology Group grouping. Conclusions Our study showed a novel coordinately prognostic role of ALK and MYCN protein expression in neuroblastoma and is the first report to demonstrate the correlation between ALK and MYCN protein expression in primary neuroblastoma tumours.