Evaluation Of Targeted Efficacy By MSCT Manifestations In EGFR-mutated Peripheral Lung Adenocarcinoma

Objective To study chest computed tomography(CT)in tyrosine kinase inhibitor(TKI)treatment of epidermal growth factor receptor(EGFR)-mutant adenocarcinoma.Methods CT and clinical data of 131 patients(from Aplril 2014 to February 2018)with peripheral lung adenocarcinoma confirmed to be mutation of EGFR gene by postoperative pathology and genetic tests were retrospectively analyzed.There were 45 males and 86females,the age arranged from 35 to 86 years old and the average age was 60.6.Patients with confirmed EGFR gene mutations of peripheral lung adenocarcinoma and oral tyrosine kinase inhibitor(EGFR-TKI)treatment 1~2 weeks before the implementation of chest CT scan,follow-up every two to three months,observtion of the correlations between clinical features and CT signs and efficacy of EGFR-TKI.The clinical characterizations mainly include:gender and smoking history;CT signs include:size(≥30mm,<30mm),lung metastasis,lymph node metastasis(with or without),Pleural lesions(with or without),distant metastasis(with or without);among them,according to the situation of metastases in the lung,it is divided into nodular type and lymphangitis type.The evaluation criteria for EGFR efficacy include primary drug resistance and the length of progression-free survival(PFS).The difference in drug resistance in gender,smoking history,pleural effusion,distant metastasis,intra-pulmonary metastasis,and lesion location was analyzed by usingχ~2 test,the patient’s progression-free survival was related to gender and smoking history,the differences in pleural effusion,distant metastasis,metastasis to the lung,and location of lesions were analyzed using Kaplan-and log Rank survival analysis,Univariate Cox regression analysis and multivariate Cox regression analysis were performed to analyze the risk factors of progression-free survival with CT signs and clinical features of EGFR efficacy.There was a statistical significance when P was less than 0.05.Results In this study,exon 19 mutations in 73 cases(55.7%),exon 21 mutations in 58 cases(44.3%).There were 32 patients with primary drug resistance(24.4%),105 patients with progression(80.2%),and 26 patients without progress(19.8%).In the correlation analysis of drug resistance in patients with EGFR gene mutations,there was a statistically significant difference between gene mutation types,P=0.048,There was no significant difference in gender,smoking history,lesion sites in the lung,size of primary lesions,presence or absence of lymph node metastasis,the intrapulmonary metastasis,presence or absence of pleural lesions and distant metastasis,P>0.05.The Kaplan-Meier analysis of progression-free survival in patients with EGFR mutations revealed a statistically significant difference between the type of EGFR mutation and the size of the primary tumor,the median PFS was significantly longer with exon 19 mutation patients than those in exon 21,and significantly higher in patients with a primary tumor size<30 mm than in the≥30 group.There was no statistical difference between gender,presence or absence of pleural effusion,smoking,distant metastases,different sites,lymph nodes metastasis or not.The results of univariate Cox regression analysis showed that PFS was significantly longer with exon 19 mutations(HR=0.576;95%CI:0.391,0.847;P=0.005),and shorter with masses main lesions(HR,1.636;95%CI:1.098,2.438;P=0.016).In multivariate analysis,PFS was significantly longer with 19del(HR=0.571;95%CI:0.387,0.842;P=0.005)and shorter with scattered masses main lesions(HR=1.603;95%CI:1.079,2.382;P=0.005).Conclusion After EGFR-TKI treatment for EGFR-mutant in peripheral lung adenocarcinoma,mutations in exon 21 of the patients with primary resistance were significantly increased than the mutations in exon 19;the median PFS was significantly longer inpatients with exon 19 mutation;the PFS was significantly shorter in patients with primary tumors Dmax≥30mm and it is an independent risk factor for disease progression.