Distribution and clinical significance of EML4-ALK fusion gene in phase I lung cancer

Abstract

Objective To detect the mutation frequency of EML4-ALK fusion gene in lung cancer patients, and to investigate the distribution of mutation character for EML4-ALK fusion gene in Ⅰ stage lung cancer patients and clinical features as well as provide a reference for the individual treatment of lung cancer. Methods 256 fresh tumor tissue specimens of lung cancer patients were screened from the specimen bank of our hospital and all the patients had accepted the surgical treatment from February 2013 to December 2014. Total RNA was extracted and then be transcribed into cDNA, the amplification-refractory mutation system(ARMS) was used to detect mutation of EML4-ALK fusion gene. The results according to the positive control, negative control and RNA quality control for EML4-ALK fusion type were analyzed. Results During the 256 patients of Ⅰ stage lung cancer, there were 17 patients(6.64%) had mutations in EML4-ALK fusion gene. In lung adenocarcinoma mutation rate(16/207, 7.73%) was higher than that of lung squamous cell mutation rate(1/39, 2.56%), lung adeno-squamous mutation rate(0/4, 0) and large cell carcinoma(0/5, 0) of the mutation rate; young lung cancer patients(<63 years) of the mutation rate(14/139, 10.07%) was significantly higher than the high age of lung cancer patients(≥63 years old) mutation rate(3/117, 2.56%), P=0.009. EML4-ALK fusion with tumor invasion and visceral pleura group incidence(9/80, 11.25%) was significantly higher than that of non-invasive and visceral pleura group incidence rate(8/176, 4.55%), P=0.045. Conclusion The occurence of EML4-ALK fusion correlates with patients’ age as well as whether visceral pleura is invaded, type 1 EML4-ALK fusion was detected more in phase I lung cancer patients. Key words: Lung cancer; EML4-ALK fusion protein, human; Molecular target therapy