Clinicopathologic Features Of Patients With Non-small Cell Lung Cancer Harboring The EML4-ALK Fusion Gene: A Meta-analysis

ObjectiveTo compare the frequency of the EML4-ALK fusion gene in patients with differentclinicopathologic features and to identify an enriched population of patients withNSCLC and the EML4-ALK fusion gene.MethodThe Pubmed and Embase databases for all articles on the association between theEML4-ALK fusion gene and NSCLC were searched up to August2013. A criteria listand exclusion criteria were established to screen the studies. The frequency of theEML4-ALK fusion gene and the clinicopathologic features, including gender, smokingstatus, pathologic type, and EGFR status were abstracted.ResultsThirteen articles consisting of3347NSCLC cases were included in themeta-analysis. A significant lower EML4-ALK fusion gene positivity rate wasassociated with smoking status (pooled OR=0.34,95%CI=0.23-0.49, P<0.0001). Asignificantly higher EML4-ALK fusion gene positivity rate was associated withadenocarcinomas (pooled OR=2.31,95%CI=1.44-3.71, P=0.0005). There was nosignificant association between the frequency of EML4-ALK and gender (pooled OR=0.64,95%CI=0.38-1.06, P=0.0806). We found that a significantly lower EML4-ALKfusion gene positivity rate was associated with EGFR (pooled OR=0.14,95%CI=0.04-0.44, P=0.0008). No publication bias was observed in any meta-analysis (allP-value of Egger’s test>0.05). ConclusionThe present meta-analysis revealed that the EML4-ALK fusion gene is highlycorrelated with a never/light smoking history and the pathologic type ofadenocarcinoma, and is largely mutually exclusive of EGFR.