EGFR-TKI is effective regardless of treatment timing in pulmonary adenocarcinoma with EGFR mutation

Although epidermal growth factor receptor–tyrosine kinase inhibitors (EGFR–TKIs) have become key therapeutic agents for non-small cell lung cancer (NSCLC) patients with EGFR mutation, little is known about the efficacy of EGFR–TKIs according to different treatment timings. A total of 1,250 patients with NSCLC were screened for EGFR mutations at a single institution between March 2006 and May 2010. The efficacy of EGFR–TKIs in terms of response rate (RR), progression-free survival (PFS), and overall survival (OS) were compared according to the treatment timing. Among the 437 patients (36.1 %) with EGFR mutation, we analyzed 222 patients who received EGFR–TKI treatment. With a median follow-up duration of 27.5 months (range 8.3–69.2), EGFR–TKI was given to 97 (43.7 %), 109 (49.1 %), and 16 (7.2 %) patients as first-line, second-line, and third-line therapy, respectively. All three groups showed similar RR (71.1, 72.5, and 75.0 %, respectively) to EGFR–TKI (p = 0.802). No significant difference was observed according to treatment timing of EGFR–TKI in terms of PFS (median 10.6, 13.0, and 10.4 months; p = 0.670) and OS (median 20.5, 26.2, and 17.1 months; p = 0.142). The treatment timing of EGFR–TKI still showed no association with PFS or OS after adjusting significant prognostic factors including performance, disease status, and EGFR mutation types. EGFR–TKIs showed similar efficacy in patients with EGFR mutation-positive adenocarcinoma in terms of RR, PFS, and OS irrespective of treatment timing. Although EGFR–TKIs are currently the treatment of choice of first-line treatment in patients with EGFR-positive tumors, the sequential treatment with EGFR–TKI could be a reasonable option when EGFR mutation status cannot be obtained in a short time.