EGFR and non-small cell lung carcinoma: The inconsistent results, the intriguing role of EGFR mutations, the influence of patients selection, and the lack published meta-analysis that systematically examined the overall efficacy of gefitinib in the frontline setting in patients with locally advanced or metastatic NSCLC, have prompted the current meta-analysis that intended to examine the potential benefit of gefitinib in that setting.