Correlation Of CT Signs And Pathological Features With EGFR Gene Mutation Status In Peripheral Pulmonary Invasive Adenocarcinoma

Objective: To investigate the correlation of CT signs and pathological features with epidermal growth factor receptor(EGFR) gene mutation status in peripheral pulmonary invas ive adenocarcinoma.Materials and Methods: 193 cases of surgical specimens with pathologically confirmed peripheral pulmonary invasive adenocarcinoma were collected.Amplification refractory mutation system(ARMS) was applied to detect the mutation of EGFR gene of all cases.The CT signs and pathological characteristics were retrospectively analyzed.Results: In 193 patients with peripheral pulmonary invas ive adenocarcinoma,the total mutation rate of EGFR gene was 62.2%(120/193).In regard to CT signs, the maximum diameter of tumor(Dmax) in axial images in EGFR gene mutation patients and wild type patients was(2.52±1.01)cm and(3.11±1.34)cm respectively,and the difference was statistically significant(P <0.05).Receiver operating characteristic(ROC) results indicated that Dmax=2.01 cm was the diagnosis threshold in forecasting EGFR gene mutat ion,with the sensitivity and specif icity of 79% and 64%, respectively.The mutation rate in tumors with ground-glass opacity(GGO) was 78.0%,which was higher than that in those without(56.6%)(P<0.05).The mutation rate in tumors without cystic airspaces was 65.5%, which was higher than that in those with(40.0%)(P<0.05).No obvious correlation was observed between EGFR gene mutation rate and other CT signs of tumors involving ground-glass opacity/tumor ratio(G/T),lobulat ion,spiculat ion, pleural retraction,vascular convergence,air bronchogram and vacuole sign(P>0.05). In regard to pathological features, EGFR mutation occurred more frequently in the subtype with lepidic-predominant than in other subtypes(77.5% vs. 58.2%, P<0.05).In contrast, EGFR mutation occurred less commonly in the subtype with solid-predominant than in other subtypes(26.3% vs. 66.1%, P<0.05).Addit ionally,EGFR mutat ions were detected more frequently in tumors without lymph node metastases than in those with(66.9% vs. 50.9%, P<0.05).Conclusion: The CT signs and pathological features may be useful indicators to predict EGFR gene mutation in peripheral pulmonary invasive adenocarcinoma.Dmax smaller than 2.01 cm,lacking cystic airspaces and involving GGO component on CT scans as well as lepidic predominance and no lymph node metastasis can predict higher EGFR gene mutat ion rate in per ipheral pulmonary invasive adenocarcinoma.