Detection of EML4-ALK fusion gene in non-small cell lung cancer and correlation with EGFR and K-ras gene mutation

Abstract

Objective To detect the EML4-ALK fusion gene and the correlation with epidermal growth factor receptor (EGFR) and K-ras gene mutation in non-small cell lung cancer. Methods Gene sequencing was used to detect the EGFR (exons 18, 19, 20, 21) and K-ras (codons 12, 13, 61) gene mutation status in 98 patients with non-small cell lung cancer and the EML4-ALK fusion gene was identified by fluorensce polymerase chain reaction.The correlation of EML4-ALK fusion gene withe EGFR and K-ras gene mutation was analyzed by χ2 test. Results In 98 patients, six specimens (6.1%) were identified with EML4-ALK fusion gene.EGFR mutation rate was 32.7% and K-ras mutation rate was 21.4%.EML4-ALK fusion gene was related with the age of the patients (χ2=5.35, P=0.021), and had no relationship with gender (χ2=0.48, P=0.491), smoking (χ2=0.11, P=0.739), histological type (χ2=1.65, P=0.648) and the degree of differentiation (χ2=1.59, P=0.452). There was no patient who had EGFR, K-ras mutation and EML4-ALK gene fusion at the same time. Conclusions EML4-ALK fusion gene defines a new molecular subset of non-small cell lung cancer.EML4-ALK fusion gene is related with the age of patients with non-small cell lung cancer.EML4-ALK fusion gene is mutually exclusive to EGFR and K-ras gene mutation. Key words: Non-small cell lung cancer; Mutation; Epidermal growth factor receptor; K-ras; EML4-ALK fusion gene