The Correlation Between EGFR Mutation And Clinicopathologic Features In Lung Adenocarcinoma

Objective:1.To explore the correlation between epidermal growth factor receptor(EGFR)mutation state and the clinical characteristics,expression of thyroid transcription factor1 in the primary lung adenocarcinoma patients.2.To explore the difference of clinical characteristics between patients with exon 19 deletion and those with exon 21 point mutation,the two types are common in EGFR mutation.3.Screening the advantage groups of EGFR mutations,and optimize the details in order to achieve the accurate treatment.Methods:1.The 188 cases of lung adenocarcinoma patients who diagnosed by pathology were collected from XX hospital since May 2013 to October 2015,we analyzed their EGFR mutation station,and collected and recorded clinical data of all cases,including the patients’ name,hospital number,gender,age,smoking history(no smoking history was defined as a lifelong smoking 100cigarettes or less),operation history,clinical TNM staging,lymph node metastasis,distant metastasis,tumor location,maximum diameter of tumor,thyroid transcription factor 1 level.2.EGFR gene was detected by Taqman-ARMS,and thyroid transcription factor-1 expression detected by immunohistochemical method.3.Using SPSS 17.0 statistical software for data processing.Pearson’s chi-square test or Fisher’s exact test was used to analysed the relationship between EGFR mutation and classification data,such as gender,smoking history,operation history,lymph node metastasis,distant metastasis,tumor location,thyroid transcription factor 1.The correlation between EGFR mutation and ranked data or counting data,such as maximum diameter of tumor and clinical staging.Multivariate logistic regression model was used to further analyses the independent predictors of EGFR mutation in primary lung adenocarcinoma.Results:1.EGFR mutation status1.1 The EGFR mutation state of 188 cases was detected by Taqman-ARMS,and mutation rate is 66.5%in lung adenocarcinoma.1.2 Mutations are mainly concentrated in the region of the 18-21 exon(63.8%),at the same time there is also double mutation(2.7%).1.3 The mutation rate of exon 18-21 are 2.1%,23.9%,3.2%and 34.6%respectively,and the double mutation rate is 2.7%.19 exon and 21 exon mutation are the most common.2.The relationship between EGFR mutation and clinical features According to gender,age,smoking history,operation history,distant metastasis,clinical staging,lymph node metastasis,tumor location,we divided the 188 lung adenocarcinoma patients groups,and analyzed the relationship between these features and EGFR mutation.Results show that:2.1 EGFR gene mutation in women is higher than men(73.1%vs 57.5%,P=0.025).2.2 The patients whose tuomr located in the upper lobes are more likely to happen EGFR gene mutation(72.4%vs 54.1%,P=0.013).2.3 Maximum diameter of tumor with EGFR mutation is smaller(Mean Rank 88.28 vs 106.85,P=0.027),the proportion of<2 cm group is the largest(76.3%).3.The relationship between EGFR mutation and TTF-1 In 188 lung adenocarcinoma patients,48 cases detect TTF-1 by immunohistochemical method.3.1 Among them,TTF-1 positive 38 cases,accounting for 79.2%,negative 10 cases,accounting for 20.8%.3.2 Chi-square test is used to analyze the relationship between EGFR mutation and TTF-1 level,the results show that there are correlation between them,the difference is statistically significant.The EGFR mutation rate is significant higher in TTF-1 positive group than negative group(71.1%vs 30%,P=0.027).4.Subgroup analysis4.1 Subgroup analysis in different EGFR mutation types show that:4.1.1 The rate of exon 19 mutations in TTF-1-positive specimens is higher than TTF-1negative(50%vs 10%,P=0.031),There is no statistical difference of the two exons 21 mutation rate(15.8%vs 10%,P=0.546).4.1.2 The upper lobe tumor prone to 21 exon mutations(39.04%vs 24.6%,P=0.046).There is no statistical difference of the two exons 19 mutation rate(23.6%vs 24.6%,P=0.546).4.2 The difference of tumor location with EGFR mutations in different gender Male patients with tumors in the upper lobes are more likely to occur EGFR mutation(69.1%vs 32%,P=0.002).There is no statistical difference of the two in female(75%vs 69.4%,P=0.539).5.Multivariate logistic regression analysis showed that gender(OR=0.375,95%CI 0.177-0.791,P=0.01)and tumor location(OR=2.37,95%CI1.234-4.552,P=0.01)are the independent predictor of EGFR gene mutation.Conclusion:1.EGFR mutation is associated with gender,the EGFR gene mutation rate of female is higher.2.EGFR mutation is associated with tumor’s location,the upper lobe tumor of EGFR gene mutation rate and exon 21 mutation rate is higher.3.EGFR mutation is associated with TTF-1,TTF-1-positive patients of EGFR gene mutation rate and exon 19 deletion rate is higher.4.To some extent,gender and tumor location can predict the advantage groups of EGFR mutations.