Fig. 4

Odds ratio (OR) for overall response rate (ORR) of the included studies. Abbreviations:hazard ratio (HR); 95 % confidence interval (95 % CI); anti epidermal growth factor receptor target drugs for selected patients subgroup (EGFR/selected); anti vascular endothelial growth factor receptor target drugs for unselected patients subgroup (EGFR/unselected); anti epidermal growth factor receptor target drugs for unselected patients subgroup (VEGFR/unselected)