Research On Correlation Between EGFR Gene Mutation In Pulmonary Adenocarcinoma And CT Findings

Objective: Investigate the correlation between EGFR gene mutation in pulmonary adenocarcinoma and CT findings,and seek a noninvasive method to predict EGFR gene mutation effectively and guide the clinical practices.Method: Two hundred and forty-seven(247)patients were included,who were diagnosed pathologically with pulmonary adenocarcinoma from Jan 1,2013 to May 31,2016,and the imaging data of all patients were analyzed retrospectively.Inclusion Criteria:(1)Confirmed as pulmonary adenocarcinoma by surgery or biopsy;(2)naive to any antitumor therapy including chemotherapy before CT;(3)complete imaging data;(4)EGFR gene test.The 247 patients complying with the inclusion criteria included 130 males and 117 females,aged 28-91 years(mean 60±11 years).The wild type EGFR group consisted of 153 patients,the EGFR mutation group consisted of 94 patients,including 3 patients with positive EGFR18 exon mutation,40 patients with positive EGFR19 exon mutation,14 patients with positive EGFR20 exon mutation,and 44 patients with positive EGFR21 exon mutation.EGFR gene mutation was detected by the amplification refractory mutation system(ARMS)technique in combination with the tissue micromutation detection technique by Taqman-MGB probe fluorescent quantitative PCR.The CT scan scope was from apex pulmonisto costodiaphragmatic recess;the scanning equipment was: Siemens 64-multi detector spiral CT and Siemens dual-source CT(FLASH).The patient inhaled continuously,and then held his/her breath and received scanning.The scanning parameters were: Slice thickness 1.0 mm,slice space 0.8 mm,scanning voltage 120 kV,tube current 100 mAs,matrix 512×512,scan window width,window level-500 Hu.The images were reconstructed by estimation method,and were 3D-reconstructed as required.The contents of CT imaging analysis included: HRCT signs included mass size(the long and short diameters of the largest level of tumor were recorded),blood vessel aggregation,ground glass halo signs surrounding the tumor,tracheal truncation signs,lobulation signs,air bronchogram,pleural indentation signs,spiculation signs,cavity signs,vacuole signs,hydrothorax,metastasis lesion of bilateral lungs,pulmonary cancerous lymphangitis,and distant metastases.The image analysis of All CT signs was conducted through the PACS system by two senior imaging attending doctors.The conclusions were recorded,which were obtained by single factor analysis and multi-factor analysis.Results: 1.Comparison of CT signs between the EGFR Gene Mutation Group and Wild Type Group: The incidence of metastasis of bilateral lungs and distant metastasis in females in the EGFR gene mutation group were higher than those in the wild type group(?2 values were 6.905,4.134,and 12.677,and P values were 0.009,0.042,and 0.000).The probability of blood vessel aggregation in EGFR gene 19 exon mutation group was higher than that in the non-mutation group(?2=8.916,P=0.003).The ages of the patients in the EGFR gene 20 exon mutation group were younger than those of the patients in the non-mutation group(t=-2.858,P=0.005),and the incidences of hydrothorax and distant metastasis were lower than those in the non-mutation group(?2 values were 4.975 and 4.216,and P values were 0.026 and 0.040).The ages of the patients in the EGFR gene 21 exon mutation group were younger than those of the patients in the non-mutation group(t=2.760,P=0.006),and the incidences of hydrothorax and distant metastasis were lower than those in the non-mutation group(?2 values were 4.958,10.330,and 7.135,and P values were 0.026,0.001,and 0.008).2.Logistic regression analysis of the relevant CT signs in the EGFR gene mutation group: EGFR gene mutation was related with female sex and distant metastasis(OR values were 2.114 and 2.794,and P values were 0.006 and 0.000).EGFR gene 19 exon mutation was related with blood vessel aggregation signs(OR=3.088,P=0.004).EGFR gene 20 exon mutation was related with age(OR=0.942,P=0.009),and significantly related with hydrothorax(OR=5.408,P=0.034).EGFR gene 21 exon mutation was related with age,spiculation signs,and distant metastasis(OR values were 1.047,2.503,and 3.228,and P values were 0.006,0.012,and 0.005).3.Analysis results of HRCT signs in the EGFR gene mutation group: The EGFR mutation probability in females was high than that in males(?2=6.905,P=0.009).The probability of EGFR gene mutation in patients with metastasis of bilateral lungs was higher than that in patients without metastasis of bilateral lungs(?2=4.134,P=0.042).The probability of EGFR19 exon mutation in patients with blood vessel aggregation signs was higher than that in patients without blood vessel aggregation signs(?2=8.916,P=0.003).The probability of EGFR21 exon mutation in patients with pleural traction signs was higher than that in patients without pleural traction signs(?2=4.958,P=0.026).The probability of EGFR21 exon mutation in patients with spiculation signs was higher than that in patients without pleural traction signs(?2=10.330,P=0.001).The probability of EGFR20 exon mutation in patients with hydrothorax was higher than that in patients without hydrothorax(?2=4.975,P=0.026).The probabilities of EGFR20 exon,EGFR21 exon,and EGFR mutation in patients with distant metastasis were higher than those in patients without distant metastasis(?2 values were 4.216,7.135,and 12.677,and P values were 0.04,0.008,and 0.000).The above results were consistent with the results in Part 1.Conclusion: 1.EGFR gene mutation in pulmonary adenocarcinoma is correlated with CT Findings to some extent.2.HRCT may predict EGFR gene mutation to some extent.