Clinicopathologic features of patients with non-small cell lung cancer harboring the EML4-ALK fusion gene: a meta-analysis..     ///    "A significant lower EML4-ALK fusion gene positive rate was associated with smokers (pooled OR?=?0.40, 95% CI?=?0.30-0.54, P<0.00001). "    ///    "The frequency of the EML4-ALK fusion gene and the clinicopathologic features, including smoking status, pathologic type, gender, and EGFR status were abstracted. "    ///    This meta-analysis was conducted to compare the frequency of the EML4-ALK fusion gene in patients with different clinicopathologic features and to identify an enriched population of patients with NSCLC harboring EML4-ALK fusion gene.     ///    The Pubmed and Embase databases for all studies on EML4-ALK fusion gene in NSCLC patients were searched up to July 2014.     ///    The key demographic and pathologic features associated with EML4-ALK fusion gene have not been definitively established.     ///     The frequencies of EML4-ALK fusion gene in non-small cell lung cancer (NSCLC) with different clinicopathologic features described by previous studies are inconsistent.     ///    "We found that a significantly lower EML4-ALK fusion gene positivity rate was associated with EGFR mutation (pooled OR?=?0.07, 95% CI?=?0.03-0.19, P<0.00001). "    ///    "This meta-analysis revealed that the EML4-ALK fusion gene is highly correlated with a never/light smoking history, female and the pathologic type of adenocarcinoma, and is largely mutually exclusive of EGFR.. "    ///    "A significantly higher EML4-ALK fusion gene positivity rate was associated with adenocarcinomas (pooled OR?=?2.53, 95% CI?=?1.66-3.86, P<0.0001) and female (pooled OR?=?0.61, 95% CI?=?0.41-0.90, P?=?0.01). "