Epidermal Growth Factor Receptor Mutation as a Risk Factor for Recurrence in Lung Adenocarcinoma

The presence of epidermal growth factor receptor (EGFR) mutations is an established prognostic factor for patients with advanced lung adenocarcinoma. Here, we examined whether EGFR mutation status is a prognostic factor for patients who had undergone surgery.Clinicopathologic data from 1,463 patients who underwent complete surgical resection for lung adenocarcinoma between 2005 and 2012 were collected. Differences in postoperative recurrence-free survival and overall survival according to EGFR mutation status were evaluated.Of 835 eligible patients, the numbers of patients with wild-type EGFR (WT), exon 19 deletion (Ex19), and exon 21 L858R (Ex21) were 426, 175, and 234, respectively. Patients with Ex19 had a significantly higher incidence of extrathoracic recurrence than patients with Ex21 (p = 0.004). The 5-year recurrence-free survival rates for patients with WT, Ex19, and Ex21 were 63.0%, 67.5%, and 78.2%, respectively. The Ex21 group had a significantly longer recurrence-free survival than the WT group (p0.001) and the Ex19 group (p = 0.016). The 5-year overall survival for patients with WT, Ex19, and Ex21 were 76.9%, 86.5%, and 87.5%, respectively. Patients with Ex19 and Ex21 had a significantly longer overall survival than patients with WT (Ex19, p = 0.009; Ex21, p0.001). Multivariate analysis for recurrence-free survival showed that Ex19 was significantly associated with a worse prognosis than Ex21 (p = 0.019).Patients with Ex19 had significantly shorter recurrence-free survival and had extrathoracic recurrence more frequently than patients with Ex21 among patients with resected lung adenocarcinoma, implying that Ex19 could be a worse prognostic factor.