Baseline characteristics of the included trials in the meta-analysis.

Note: TKIs = tyrosine kinase inhibitors, PS = performance status, E = erlotinib, G = gefitinib, DDP = cisplatin, CBP = carboplatin, AUC = area under the curve, GEM = gemcitabine, q4w = every four weeks, vs = the combined regimen versus chemotherapy or TKIs monotherapy, NA = not available, TAX = paclitaxel. †Sequential administration of erlotinib following gemcitabine/platinum chemotherapy, rather than concurrent administration as the other trials. ‡Only included patients treated with gefitinib 250 mg/d. &Data from trials INTACT 1and 2 together.