Radiogenomic correlation in lung adenocarcinoma with epidermal growth factor receptor mutations: Imaging features and histological subtypes.

OBJECTIVES: To correlate imaging features of resected lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation and the IASLC/ATS/ERS classification histological subtypes.
METHODS: In 250 consecutive patients with resected lung adenocarcinoma, EGFR mutation status was correlated with demographics, imaging features including ground-glass opacity (GGO) proportion and the IASLC/ATS/ERS classification histological subtypes.
RESULTS: EGFR mutations were significantly more frequent in women (54.5 % vs. 38.1 %, p = 0.011) and in never-smokers (54.7 % vs. 35.3 %, p = 0.003). GGO proportion was significantly higher in tumours with EGFR mutation than in those without (30.3 ± 33.8 % vs. 19.0 ± 29.3 %, p = 0.005). EGFR mutation was significantly more frequent in tumours with GGO ≥ 50 % and tumours with any GGO (p = 0.026 and 0.008, respectively). Adenocarcinomas with exon 19 or 21 mutation showed significantly higher GGO proportion than that in EGFR wild-type tumours (p = 0.009 and 0.029, respectively). Absence of GGO was an independent predictor of negative EGFR mutation (odds ratio, 1.81; 95 % confidence interval, 1.16-3.04; p = 0.018).
CONCLUSIONS: GGO proportion in adenocarcinomas with EGFR mutation was significantly higher than that in EGFR wild-type tumours, and the absence of GGO on CT was an independent predictor of negative EGFR mutation. KEY POINTS: • Ground-glass opacity (GGO) proportion is significantly higher in EGFR-mutated adenocarcinomas • Exon 19 or 21 mutated adenocarcinomas shows significantly higher GGO proportion • GGO absence is an independent predictor of negative EGFR mutation in lung adenocarcinomas.