Relationship Between EGFR Mutation Status And Histological Subtype And Survival In The New Classification Of Lung Adenocarcinoma

Objective To investigate the correlation between the mutation status of EGFR and histological subtypes and survival of lung adenocarcinoma.We expect to be able to guide clinical options and to better assess prognosis.Methods To collect the survival data of patients with IIa-IIIa stage lung adenocarcinoma who were treated by surgical resection from June 2009 to August 2011 in Department of thoracic surgery of the 105 th hospital of PLA.Histological classification according to the new classification criteria of lung adenocarcinoma.Detection of EGFR gene.Comparison of EGFR gene mutation positive with EGFR mutation in patients with negative(wild-type)disease for 2 years progression free survival(PFS)and 5 year overall survival(OS).Analysis and comparison of the effects of EGFR mutation on the survival of patients.Restults The mutation rate of EGFR gene was 46.6% in 120 patients with lung adenocarcinoma,The most common mutation sites were exon19(44.6%)and exon 21(42.8%).In all types of invasive lung adenocarcinoma,The most common histological type was the Acinar predominant(55.8%),and the second was the Lepidic predominant(25.8%).The positive rates of EGFRmutations in these two histologic types(The Acinar predominant 61.2% VS the Lepidic predominant 44.7%),and the EGFR wild type(The Acinar predominant 55.3% VS the Lepidic predominant 33.8%),However,there was no significant difference in the EGFR mutation rate between the two histologic subtypes(P=0.192).By comparing the survival time analysis,2years of disease free survival time in lung adenocarcinoma(EGFR mutation positive 55.3% EGFR VS mutant wild type 55.6%,P=0.367),Total survival time of 5 years(EGFR mutation positive 55.5% EGFR VS mutant wild type40.6%,P=0.143).But in patients with stage IIIa,Patients with positive EGFR mutations were significantly higher than those with EGFR negative mutations for 5 years OS(EGFR mutation was positive in 41.7% VS EGFR mutant wild-type 25%,P=0.456),the difference was not statistically significant.Conclusion In adenocarcinoma of the lung,There was no correlation between histological subtype and EGFR mutation.The mutation state of EGFR is not a factor influencing the survival time of lung adenocarcinoma.but in patients with stage IIIa,the EGFR mutation was more responsive to survival in patients who had been staging late.