Abstract: ObjectiveTo observe EML4ALK fusion gene mutation expression rate in serum and cancer tissue of patients with nonsmall cell lung cancer (NSCLC) in Chinese populations, and the consistency of mutation in serum and cancer tissues, and the feasibility of realtime, dynamic detection of EML4ALK fusion gene therapy by using FQPCR.Methods123 cases of serum and 98 cases of tissue of NSCLC patients were detected by fluorescence quantitative polymerase chain reaction, and 77 cases of which were matched. The clinical curative effects of ALK inhibitor (crizotinib) were analyzed.Results13 rearrangement in 123 (10.6%) of the patients′serum samples and 11 rearrangement in 98 (11.2%) tumor tissue. EML4ALK rearrangement were mainly discovered in adenocarcinoma (χ2=4.083, P=0.036)， and nonsmokers in NSCLC(χ2=5.326, P=0.019). The consistency of patients with EML4ALK matched tumor tissue and serum reached 66.7% (6/9, κ=0.779). The EML4ALK fusion gene rearrangement in patients receiving ALK inhibitor (crizotinib) treatment achieved significant benefit.  ConclusionThe EML4ALK rearrangement mainly exists in the serum and tumor tissue of adenocarcinoma and nonsmokers in NSCLC. When tumor tissue samples are unable to be obtained, FQPCR can be used to detect serum EML4ALK fusion gene mutation for selecting NSCLC patients suitable for crizotinib therapy instead of tumor tissue.

Key words: Carcinoma, nonsmall cell lung, Reverse transcriptase polymerase chain reaction, EML4ALK