In the present study, EGFR-mutant advanced NSCLC patients without preexisting brain metastases showed no significant difference in the cumulative rates of CNS progression (P = 0.156) and the median nTTP (18 months vs 16 months, P = 0.392) between the erlotinib group and gefitinib group. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.