The patients enrolled in the Yamamoto study were of relatively good health, with no brain metastases and with a higher proportion of patients with an Eastern Cooperative Oncology Group performance status (ECOG-PS) score of 0, which may have contributed to the favorable PFS and OS data compared to other studies in advanced EGFR-positive NSCLC. This evidence concerns the gene EGFR and non-small cell lung carcinoma.