EGFR-TKI benefit for NSCLC patients with EML4-ALK rearrangement.

e18035 Background: EML4-ALK rearrangement defines a new molecular subtype of non-small-cell lung cancer (NSCLC). To identify the biological profiles of these patients, we examined the clinico-pathologic characteristics and treatment outcomes of NSCLC patients based on EML4-ALK and EGFR mutations. Methods: Patients with stage IV NSCLC were screened for EML4-ALK rearrangement and EGFR mutations at Peking University Cancer Hospital. EML4-ALK was identified using fluorescent in situ hybridization (FISH) confirmed by immunohistochemistry (IHC), and EGFR mutations were determined using denaturing high-performance liquid chromatography (DHPLC). Results: Of the 151 patients screened, 113 had complete follow-up data as an analysis set. The incidence of EML4-ALK was 9.7% (11/113) using FISH, in which 10 cases had sufficient specimens for IHC confirmation and all were positive. Overall, EML4-ALK and EGFR mutations were largely mutually exclusive (p = 0.033), although two patients harbored concurrent mutations. EML4-...