Relationships between EGFR Mutation Status of Lung Cancer and Preoperative Factors - Are they Predictive?

Abstract

<b>Background:</b> The epidermal growth factor receptor (EGFR) mutation status of lung cancer is importantbecause it means that EGFR-tyrosine kinase inhibitor treatment is indicated. The purpose of this prospectivestudy is to determine whether EGFR mutation status could be identified with reference to preoperative factors.Materials and <br/><b>Methods</b>: One hundred-forty eight patients with lung cancer (111 adenocarcinomas, 25 squamouscell carcinomas and 12 other cell types) were enrolled in this study. The EGFR mutation status of each lungcancer was analyzed postoperatively. <br/><b>Results</b>: There were 58 patients with mutant EGFR lung cancers (mutantLC) and 90 patients with wild-type EGFR lung cancers (wild-type LC). There were significant differences ingender, smoking status, maximum tumor diameter in chest CT, type of tumor shadow, clinical stage betweenmutant LC and wild-type LC. EGFR mutations were detected only in adenocarcinomas. Maximum standardizeduptake value (SUVmax:3.66±4.53) in positron emission tomography-computed tomography of mutant LC wassignificantly lower than that (8.26±6.11) of wild-type LC (p<0.0001). Concerning type of tumor shadow, thepercentage of mutant LC was 85.7% (6/7) in lung cancers with pure ground glass opacity (GGO), 65.3%(32/49)in lung cancers with mixed GGO and 21.7%(20/92) in lung cancers with solid shadow (p<0.0001). For the resultsof discriminant analysis, type of tumor shadow (p=0.00036) was most significantly associated with mutant EGFR.Tumor histology (p=0.0028), smoking status (p=0.0051) and maximum diameter of tumor shadow in chest CT(p=0.047) were also significantly associated with mutant EGFR. The accuracy for evaluating EGFR mutationstatus by discriminant analysis was 77.0% (114/148). <br/><b>Conclusions</b>: Mutant EGFR is significantly associatedwith lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chestCT. Preoperatively, EGFR mutation status can be identified correctly in about 77 % of lung cancers.