Clinical Features Of EGFR Double Mutation In Non-small Cell Lung Cancer

Objective: Lung cancer is the tumor with the highest morbidity and mortality in China and the world.Traditional radiotherapy and chemotherapy have entered the plateau stage,but the emergence of molecular targeted drugs has brought new dawn to the treatment of lung cancer.Epidermal Growth Factor Receptor(EGFR)mutation is the most common type of mutation in non-small cell lung cancer(NSCLC).And the molecular targeted drugs targeting EGFR mutations have been widely used clinically.It has been widely recognized that the clinical characteristics of epidermal growth factor receptor(EGFR)in patients with non-small cell lung cancer(NSCLC).The objective remission rate and progression-free survival time were significantly prolonged after EGFR tyrosine kinase inhibitors(TKIs)treatment.However,thosewere not clear that the clinical characteristics of EGFR double mutation patients and the sensitivity to EGFR-TKIs therapy.The purpose of this study was to investigate the genotyping,clinical features and therapeutic effect of EGFR-TKIs in all patients with EGFR double-mutant NSCLC who were admitted to our hospital.Methods: There were 1238 patients with EGFR gene who were examined in Qingdao University affiliated Hospital,which consisted of 603 patients with single mutation and 59 patients with double mutation(28 early patients and 31 advanced patients)from January 1,2015 to December 31,2016.(1)The gene analysis of the patients with single and double mutant and EGFR double mutant in early and late stage were carried out.Find out the predominant genotypes and the proportion of each genotype in patients with different mutations.(2)The clinical features of 60 patients with single mutation and 55 patients with double mutation were randomly selected and compared,including sex,smoking history,age,pathological type and TNM stage.(3)The clinical data of single mutation and double mutation patients treated with EGFR-TKIs were analyzed,including lung,craniocerebral,total abdomen,bone scan and blood index of tumor markers.Comparison of the efficacy of double mutation and single mutation in advanced EGFR in the treatment of EGFR-TKIs.Result: In 55 patients with EGFR double mutation,only 6 cases were complex mutations of common sensitive single mutation gene,the other 49 cases were combined with rare single mutation gene,the G719X/S768 I genotype was the most common gene mutation(14 / 32).And the probability of combined drug resistance gene reaches 38.18%.Among the 60 patients with single mutation of EGFR,63.33 percent were female,68.33 percent had no history of smoking,and 96.67 percent had adenocarcinoma.Among the 55 patients with double mutation,18 / 20 mutation was found in 20 people(36.36%)and there were 19 / 20 mutation in 8 people(14.55%),and there were 19/ 21 mutation in 9 people(16.36%)and 20 / 21 mutations in 18 cases(32.73%).The patients with double mutation and single mutation had higher than 0.05 in sex,smoking history,age,pathological type and TNM stage.There was no significant difference in clinical characteristics between the two groups.In the 19 patients with advanced EGFR double mutation,the ORR of the first-line EGFR-TKIs was 36.8%,the DCR was 68.4%,the mean PFS was 7.4 months,and the median PFS was 6.0 months.And in the 20 patients with advanced EGFR single mutation,the ORR of first-line EGFR-TKIs was 60%,DCR was 90%,mean PFS was 13.9 months,and median PFS was 12.0 months.There was significant differences in the two groups of PFS(P=0.003).In the 3 patients who only received EGFR-TKIs,the mean PFS was 17.0 months and the median PFS was 15.0 months.Conclusions: The genotype of EGFR double mutation patients is the most common with rare single mutation gene.The G719X/S768 I genotype is the most common and has a high proportion of combined drug resistance genes.There was no significant difference between the clinical features of EGFR double mutation patients and the single mutation patients,which were all in line with women,no smoking history,and most of the patients with adenocarcinoma.In patients with double mutations,patients treated with a generation of EGFR-TKIs are lower than patients with a single mutation,and the two-way EGFR-TKIs susceptible to rare mutations may be more suitable for patients with EGFR double mutations,due to the susceptibility of patients with double mutations to combine rare single-mutational genes.