CT Features of Epidermal Growth Factor Receptor-Mutated Adenocarcinoma of the Lung: Comparison with Nonmutated Adenocarcinoma.

INTRODUCTION: The purpose of this study was to analyze the high-resolution computed tomography (HRCT) features of lung carcinoma on the basis of epidermal growth factor receptor gene (EGFR) mutation status.

METHODS: A total of 263 consecutive patients in whom lung adenocarcinoma was diagnosed at our institution between January 2010 and December 2011 were enrolled in the study. All patients underwent HRCT and analysis of EGFR mutation status. The HRCT findings were retrospectively analyzed for tumor size, multiple bilateral lung metastases, convergence of surrounding structures, surrounding ground-glass opacity, prominent peribronchovascular extension, air bronchogram, notch, pleural indentation, spiculation, cavity, and pleural effusions.

RESULTS: EGFR mutations were demonstrated in 103 patients (39.2%); the remaining 160 patients (60.8%) had the nonmutated type of adenocarcinoma. Compared with the nonmutated group, the mutated group had significantly higher frequencies of multiple bilateral lung metastases (p = 0.0152), convergence of surrounding structures (p < 0.0001), ground-glass opacity (p = 0.0011), and notch (p = 0.0428), but significantly lower frequencies of cavitation (p = 0.0004) and pleural effusions (p = 0.0064). The frequencies of the other CT findings were similar between the two groups. The devised prediction HRCT score for EGFR mutation was 78.4% sensitive and 70.4% specific.

CONCLUSIONS: EGFR-mutated adenocarcinoma showed significantly higher frequencies of multiple bilateral lung metastases, convergence of surrounding structures, surrounding ground glass opacity, and notch at HRCT compared with the non-EGFR-mutated type. Conversely, EGFR-mutated adenocarcinoma showed cavity and pleural effusions less frequently than the nonmutated type did.