Epidermal Growth Factor Receptor Mutation Status and Treatment Outcome for R0-Resected Patients with Stage 3 Non-small Cell Lung Cancer.

Background: This study aimed to investigate the association of epidermal growth factor receptor (EGFR) mutation status with treatment outcome for patients with stage 3 non-small cell lung cancer (NSCLC) who had undergone a complete (R0) resection.

Methods: The study identified 3445 NSCLC patients tested for EGFR mutations between September 2001 and December 2011 at the Sun Yat-Sen University Cancer Center. Of these patients, 224 were stage 3 patients who had undergone R0 resections.

Results: These 224 R0-resected, pathologic stage 3A and 3B patients included 150 patients with wild-type EGFR and 74 patients with EGFR mutations. During a median follow-up period of 42 months (range, 4-133 months), pathologic stage was shown to be the only prognostic factor. The 3-year overall survival (OS) rates did not differ significantly from the OS rates for the wild-type and mutant EGFR groups (62.0 vs 67.2 %; p = 0.789). Multivariate analyses indicated that the patients in the mutant EGFR group with EGFR exon 19 mutations had a better OS rate (73.0 vs 61.1 %; p = 0.026).

Conclusions: Cancer stage remained the significant prognostic factor in R0-resected stage 3 NSCLC patients. The presence of an EGFR mutation is more likely to be a predictive marker for the response to treatment with tyrosine kinase inhibitors. In the EGFR mutant group, the patients with an exon 19 mutation had better 3-year OS rates. These findings might be considered in future study designs.