Correlation of ALK expression with traditional prognostic parameters
The overall survival correlated with patient’s age (p=0.03), stage (p=0.01), morphology (p=0.036) and INRG risk groups (p=0.0001) as previously reported.15 There was no correlation of ALK protein expression with INRG subgroups although higher levels were observed in the high-risk group (Fig.4A). Univariate analysis revealed ALK protein expression did not significantly correlate with the outcome (Fig.4B); furthermore, the combination of ALK protein expression withMYCN amplification  status also revealed no association with the outcome (Fig.4C). In ALK positive cases (Table 1),MYCN  amplification revealed no association with outcome (Fig.4C). Hence, we analyzed the effect of morphology on outcome within the group of ALK positive cases which revealed that ALK positive poorly differentiated neuroblastomas had better survival (p=0.02) than the other subgroups which had almost similar overall survival (Fig.4D).