Fresh Cytology Specimen Gene Detection Of Non-small Cell Lung Cancer And Its Clinical Significance

Objective:With the development of tumor molecular biology,targeted therapy is playing a more and more important role in tumor therapy with its high selectivity,less side effects and better clinical effects,especially in NSCLC.But it is not effective for all the patients,just effective for the patients with EGFR sensitive mutation and EML4-ALK fusion gene.So NSCLC patients must be taken gene detection before accepting targeted therapy.At present,most samples used in gene detection are paraffin specimens of tumour tissues,which are very difficult to obtain for patients in advanced stage.Therefore,this study intend to use fresh cytologic specimens such as pleural effusion and fine needle aspiration to detect gene mutation.Expected to complete the following purpose:1 To explore the advantage of NSCLC patients' cytology specimens in the detection of EGFR and ALK gene,and the relationship between the EGFR gene mutation and clinical characteristics.2 To explore the efficacy of the first line using the TKI drug NSCLC patients with sensitive EGFR gene mutation tested by cytological specimens and analyze the survival time of the patients.To compared with the efficacy and survival time of NSCLC patients with sensitive EGFR gene mutation tested by tumor tissue paraffin specimens in the previous report.Methods:1 A total of 376 specimens of needle aspiration and pleural effusion were collected in the Cancer Detection Center of Fourth Hospital of Hebei Medical University.After HE staining and immunocytochemistry staining,the specimens were diagnosed by two cytology pathologists first.Then the patient's gender,age,smoking status,pathological type,type specimens wererecorded.2 The method of ARMS was used to test exon 18-21 of EGFR for 293 specimens of needle aspiration and pleural effusion of them.To observe the mutation and analyze its relationship with clinical features.3 23 specimens of pleural effusion were collected using pathological cellular collector.After direct smear,FISH method was used to observe the gene fusion of EML4-ALK.4 138 NSCLC patients with sensitive EGFR gene mutation tested by cytological specimens were Collected.According to the situation of first-line drugs,patients were divided into group A(targeted therapy group,44 cases),B(Targeted therapy plus chemotherapy group,45 cases)and C(chemotherapy group 49 cases).To compare the Objective Response Rate(ORR),Disease Control Rate(DCR),Progression-Free-Survival(PFS),Overall Survival(OS)and one-year survival rate.Results:1 Cancer cells were found in 361 specimens by HE staining.316 cases were diagnosed with NSCLC.Among 316 cases,102 cases were needle aspiration specimen,214 cases were pleural effusion specimen;307 cases were adenocarcinoma,9 cases were squamous cell carcinomas.2 Test results of the EGFR gene mutation: 288 cases of 293 patients successfully extract DNA,the success rate was about 98.3%.The mutation rate of EGFR gene was 45.1%.The mutation rate of EGFR gene in exon 18,19,20,21 were 3.8%(5/130),46.2%(60/130),3.8%(5/130),46.2%(60/130)respectively.The mutation rate of men was 37.2%(55/148),and women was53.6%(75/140),with the statistical differences(P = 0.005).The mutation rate of patients over or equal to 60 years was 45.8%(71/155),and patients under 60 was 44.4%(59/133),with no statistical difference(P= 0.806).The mutation rate of smoking patients was 35.5%(33/93),and nonsmoking patients was49.7%(97/195),with statistical difference(P = 0.023).The mutation rate of adenocarcinoma patients was 46.2%(129/279),and squamous cell carcinomas patients was 11.1%(1/9),with statistical difference(P = 0.044).The mutationrate of needle aspiration specimens was 37.4%(37/99),and pleural effusion specimens was 49.2%(93/189),with no statistical difference(P = 0.055).3 Results of testing EML4-ALK gene: 3 of the 23 pleural effusion specimens were positive.The positive rate was 13.0%.Among 3 cases,the median age was 50 and all the patients were adenocarcinoma;men,1 case,had the history of smoking and women,2cases,had no smoking history.4 The efficacy and the survival time of TKI: the ORR of group A,B and C were 81.8%,80% and 30.6%,and the DCR were 93.2%,86% and 71.4%,respectively.The median PFS were 9.5 months,7.5 months and 6 months,the median OS 19.5 months,13.25 months and 9 months,one-year survival rate were 52.3%,33.3% and 28.5%,respectively.The survival time of targeted therapy group and targeted therapy plus chemotherapy group were superior to chemotherapy group.The efficacy and survival time was same to the NSCLC patients' with sensitive EGFR gene mutation tested by tumor tissue paraffin specimens.Conclusion:1 Mutation rates tested by the method of ARMS using cytological specimens were basically same with the rates tested by previous report using tumor tissue paraffin specimens.The method with high practicability and accuracy could overcome the shortcomings of traditional sequencing method that show poor sensitivity and negative effects of formalin and paraffin wax on DNA extraction and PCR amplification.2 EGFR mutation of NSCLC patients mainly happen to female,nonsmokers,adenocarcinoma patients,but had nothing to do with age.3 In NSCLC patients with EGFR mutation,the mutation rate of pleural effusion specimens was a bit higher than needle aspiration specimens,but there was no statistically significant difference.4 EML4-ALK had served as a new therapeutic target in the treatment of NSCLC patients.The method of FISH test after exfoliated cells direct smear,was simple,repeatable and high sensitivity.It can be widely applied in clinic.5 NSCLC patients with EGFR gene mutation tested using fresh cytologyspecimens can had a higher quality of life and longer survival time.