OBJECTIVE:To study the gene mutation status of epidermal growth factor receptor(EGFR)in non-small cell lung cancer(NSCLC)patients and its relationship with clinical indexes,and to provide reference for individualized administration of EGFR-TKI in NSCLC patients. METHODS:Totally of 274 NSCLC patients from the northern of Jiangsu area were selected from our hospital during Jan. 2015-Dec. 2017. Mutation status of EGFR gene in lung tissue was determined by amplification refractory mutation system (ARMS)-TaqMan PCR assay. The relationship of EGFR gene mutation with clinical indexes as gender,age, smoking status, staging, tumor differentiation and pathological type were analyzed retrospectively. Compared with related literatures,the regional differences of EGFR gene mutation were analyzed. RESULTS:Among 274 NSCLC patients,112 patients suffered from EGFR gene mutation with total mutation rate of 40.88%. There were 50,57,3,2 cases of exon 19,exon 21,exon 20 and exon 19+21 mutation,and the types of EGFR gene mutation were delE746-A750,L858R and insH773-V774H,etc. The mutation rates of EGFR gene exon 19,exon 21 in non-smoking,early,well-differentiated and adenocarcinoma patients were 52.50%,47.24%,46.36% and 45.00%,which were significantly higher than smoking (28.57%),advanced (27.03%), poor-differentiated(31.71%)and squamous cell carcinoma(27.66%)patients,with statistical significance(P＜0.05). There was no statistical significance in mutation rates of EGFR gene exon 19 and exon 21 between male and female,≥65 year-old and ＜65 year-old patients (P＞0.05). EGFR mutation rate of NSCLC subjects from the northern of Jiangsu area was significantly higher than Shanghai area(P＜0.05);there was no statistical significance compared with Yunnan area(P＞0.05)but mutation types were different. CONCLUSIONS:There is the highest EGFR gene mutation rate in its exon 21,lesser in exon 19,rare in exon 20 and exon 19+21 among NSCLC patients from the Northern of Jiangsu area. There are obvious regional differences. The mutation rate of EGFR gene mutation exon 19 and exon 21 are associated with smoking status,staging,tumor differentiation and pathological type of NSCLC patients. The non-smoking, early stage, well-differentiated and adenocarcinoma patients are more likely to benefit from EGFR-TKI targeted therapy.

OBJECTIVE:To investigate the correlation of XRCC1 rs25487 polymorphism with the occurrence of lung cancer. METHODS:A total of 208 patients with primary lung cancer of Han nationality in Northern Jiangsu selected from the Affiliated Hospital of Xuzhou Medical University during Sept. 2015-Jul. 2016 were included in lung cancer group. A total of 214 healthy volunteers of the hospital underwent physical examination were included in control group. PCR-RFLP was used to detect the genotypes at XRCC1 rs25487 locus,and Logistic regression model was used to evaluate the correlation of genotypes with the occurrence of lung cancer. RESULTS:There was no statistical significance in the distribution of age and gender between 2 groups (P＞0.05). The proportion of smoker in lung cancer group was significantly higher than control group,with statistical significance(P＜0.05). AA,AG and GG genotypes were detected at rs25487 locus of XRCC1 gene. The frequency of AA,AG and GG genotype were 43.5%,41.1%and 15.4% in control group and 28.8%,48.6% and 22.6% in lung cancer group,respectively. The frequencies of genotypes in 2 groups were in line with Hardy-Weinberg equilibrium(P＞0.05),but there was statistical significance in genotype distribution between 2 groups(P＜0.05). Compared with AA genotype,the risk of lung cancer in individuals carrying AG genotype increased by 2.265 fold [OR＝2.265,95%CI(1.299,3.950),P＝0.040;after corrected with gender,age and smoking history OR＝2.309,95%CI(1.274, 4.185),P＝0.006],with statistical significance. The risk of lung cancer in individuals carrying GG genotype increased by 1.310 fold [OR＝1.310,95%CI(0.771,2.228),P＝0.318;after corrected OR＝1.429,95%CI(0.811,2.518),P＝0.217],without statistical significance. CONCLUSIONS:rs25487 locus mutant heterozy-gosity of XRCC1 gene is risk factor of lung cancer in Han nationality from Northern Jiangsu,and smoking can increase the risk of lung cancer.