Impact of epidermal growth factor receptor mutations on intracranial treatment response and survival after brain metastases in lung adenocarcinoma patients.

Abstract

e19030 Background: Brain metastases (BM) commonly occur in patients with lung adenocarcinoma and usually lead to a poor prognosis. Epidermal growth factor receptor (EGFR) mutation is a predictive and prognostic factor for EGFR tyrosine kinase inhibitor (TKI) treatment for lung adenocarcinoma. The present study aimed to elucidate the predictive role of EGFR mutations in BM treatment response and survival after BM in patients with lung adenocarcinoma patients. Methods: From January 2006 through February 2012, 180 of 505 lung adenocarcinoma patients developed BM during their disease course were reviewed for eligibility, and 139 patients, including 89 EGFR mutant and 50 EGFR wild-type patients, were identified for analysis. BM treatment response was assessed radiologically 1 month after start of treatment and survival data was collected. Results: EGFR mutant patients, compared with EGFR wild-type patients, had significantly greater treatment response of BM (85% vs. 53%, P = 0.001) and longer median survival after BM diagnosis (13.2 vs. 6.8 months, P < 0.001). EGFR mutation (P = 0.001) and use of EGFR TKI during treatment (P = 0.037) were independently associated with BM treatment response. Furthermore, EGFR mutation (P = 0.005), good performance status (P < 0.001) and absence of extracranial metastases (P = 0.033) correlated with better survival. Conclusions: EGFR mutation is an independent predictive factor for both BM treatment response and survival after BM in patients with lung adenocarcinoma. Further studies on incorporation of EGFR mutation status into therapeutic strategy and survival prediction system for lung adenocarcinoma with BM are warranted.