In patients who had EGFR-positive stage IV NSCLC, the median PFS was 11.1 months and median OS was 14.1 months, which is comparable to those in other studies performed worldwide.10,11 Patients who had EGFR-negative stage IV NSCLC had a significantly better PFS and OS with pemetrexed-based chemotherapy regimens. This evidence concerns the gene EGFR and non-small cell lung carcinoma.