Concomitant EGFR mutation and EML4-ALK gene fusion in non-small cell lung cancer.

10517 Background: The fusion of the anaplastic lymphoma kinase (ALK) with the echinoderm microtubule-associated protein-like 4 (EML4) and epidermal growth factor receptor (EGFR) mutations are considered mutually exclusive. Advanced non-small cell lung cancer (NSCLC) patients with EML4-ALK did not benefit from EGFR tyrosine kinase inhibitors (TKIs). Methods: Multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) followed by sequencing was performed for EML4-ALK fusion status detection. EGFR and KRAS mutations were determined by direct DNA sequencing. Positive results of EML4-ALK fusion were also confirmed by RACE-coupled PCR sequencing. Results: From April 2010 to January 2011, 412 patients (398 with NSCLC; 14 with SCLC) were tested for mutation status of EGFR, KRAS and EML4-ALK respectively. Frequency of EML4-ALK fusion was 10.6% (42/398) in NSCLC patients. No patients with SCLC were found to have positive EML4-ALK fusion. Frequency of concomitant EGFR and EML4-ALK gene mutations was 1.0% (4/3...