Effect of gefitinib on the survival of patients with recurrence of lung adenocarcinoma after surgery: A retrospective case-matching cohort study

Background Patients with lung adenocarcinoma who carry epidermal growth factor receptor ( EGFR ) gene mutations respond remarkably well to EGFR tyrosine kinase inhibitor (EGFR-TKI), gefitinib, or erlotinib. However, the effect of EGFR-TKI treatment on the prolongation of overall survival (OS) of these patients remains uncertain, although several recent studies have shown prolongation of progression free survival compared with cytotoxic chemotherapy. Methods A total of 304 patients with lung adenocarcinoma who had postoperative recurrent disease were studied. To eliminate potential biases as possible, the matching of four potential predictive factors of responsiveness to EGFR-TKI led to the identification of 81 pairs of patients (those who were treated with gefitinib and those who were not). A deletion mutation in exon 19 and a point mutation (L858R) in exon 21 of the EGFR gene were also analyzed. We compared the OS between the two groups. Results OS in the gefitinib group was significantly longer than in the control group (median, 63 vs. 41 months; p = 0.015). EGFR mutations were detected in 65 out of 129 patients (50%) in the whole sample. EGFR mutational status was not an independent prognostic factor of gefitinib benefit; rather, it was a predictive factor. Conclusions This study strongly suggested that gefitinib treatment improved OS of lung adenocarcinoma patients who had postoperative recurrence, especially those carrying EGFR mutations.