Prognostic value of epidermal growth factor receptor mutations in resected lung adenocarcinomas

The purpose of this study was to evaluate the association between epidermal growth factor receptor (EGFR) mutations and prognosis in patients with completely resected lung adenocarcinoma. A total of 131 patients were included in this study. EGFR mutation status in exons 18-21 of the tyrosine kinase-binding domain was detected using nested PCR amplification of individual exon. The chi(2) test was used to analyze the associations between EGFR mutations and the different variables. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). EGFR mutations in 18-21 exons were detected in 58 of the 131 patients (44.3 %). Smoking status (P = 0.029), N stage (P = 0.021), and pathologic stage (P = 0.048) were significantly associated with EGFR mutations. The median DFS in mutant EGFR and wild-type EGFR groups was 36.6 and 25.7 months, respectively (P = 0.533). No significant correlation was observed between EGFR mutations and OS (P = 0.564). However, patients with exon 19 mutation tended to have longer DFS than those with exon 21 mutation (46.2 vs. 21.9 months, P = 0.056), and the 1-, 2-, and 3-year OS rates were significantly higher in patients with exon 19 mutation compared to patients with exon 21 mutation (100, 96.7, 93.3 vs. 91.3, 82.6, 60.9 %, respectively, P = 0.01). Our data demonstrated that EGFR mutations do not have significant prognostic value in primary resected lung adenocarcinomas, but patients with exon 19 mutation tended to have better prognostic value compared to patients with exon 21 mutation.