Distinct features of distant metastasis and lymph node stage in lung adenocarcinoma patients with epidermal growth factor receptor gene mutations

Background: The influence of epidermal growth factor receptor (EGFR) mutation status on distant and lymph node metastasis is not fully understood. Methods: Ninety-five consecutive patients with stage IV lung adenocarcinoma, who had been examined for the EGFR mutation status, were retrospectively analyzed with regard to numbers of distant metastasis and clinical stage of lymph node metastasis at the time of diagnosis. Results: While EGFR mutation status did not influence the presence or absence of distant metastasis in the lung, brain, or liver, patients with EGFR mutations demonstrated a significantly greater number of metastatic lesions in the lung (median: 85 vs. 4, P=0.01) and the brain (11 vs. 3.5, P =0.04). On the other hand, patients with EGFR mutations showed a significantly lower lymph node staging (P<0.01). Conclusion: The presence of EGFR mutations in patients with lung adenocarcinoma correlates with lower lymph node stage and a greater number of metastatic lesions in the lung and brain. (C) 2013 The Japanese Respiratory Society Published by Elsevier B.V. All rights reserved.