Impact of the epidermal growth factor receptor mutation status on the post-recurrence survival of patients with surgically resected non-small-cell lung cancer

OBJECTIVES The impact of epidermal growth factor receptor (EGFR) status and the use of EGFR-tyrosine kinase inhibitor (EGFR-TKI) therapy have not been well discussed only in recurrent non-small-cell lung cancer (NSCLC). The purpose of this study was to identify the prognostic factors associated with post-recurrence survival after surgical resection of NSCLC in terms of the EGFR mutation status and the use of EGFR-TKI therapy. METHODS From 2000 through 2011, 1237 consecutive patients with NSCLC underwent pulmonary resection at our institution. Of these patients, 280 experienced postoperative recurrence by the end of 2012. We reviewed the cases of recurrence and analysed the predictors and length of post-recurrence survival. RESULTS The median post-recurrence survival time and the 5-year survival rate of all patients were 25 months and 20.8%, respectively. A multivariate analysis identified the Eastern Cooperative Oncology Group (ECOG) performance status (PS), brain metastasis, number of sites of recurrence and EGFR mutation status to be independent prognostic factors for post-recurrence survival. Among all cases, the median post-recurrence survival time according to the use of EGFR-TKI therapy was as follows: 49 months in the EGFR mutation-positive patients treated with EGFR-TKI therapy, 20 months in the EGFR wild or unknown cases treated with EGFR-TKI therapy and 17 months in the patients not treated with EGFR-TKI therapy. As to EGFR mutation-positive cases, the patients treated with EGFR-TKIs exhibited significantly longer post-recurrence survival time than the patients treated without EGFR-TKIs (49 vs 12 months). CONCLUSIONS It is essential for recurrent NSCLC patients to be examined for the EGFR mutation status. Patients with a positive EGFR mutation status receive significant benefits from EGFR-TKI therapy.