Clinical and computed tomography characteristics of non‐small cell lung cancer with ALK gene rearrangement: Comparison with EGFR mutation and ALK/EGFR‐negative lung cancer

BACKGROUND: The study was conducted to evaluate the clinical and computed tomography (CT) findings of non‐small cell lung cancer (NSCLC) patients to distinguish between ALK gene rearrangement, EGFR mutation, and non‐ALK/EGFR (no genetic abnormalities). METHODS: We enrolled 201 patients with primary NSCLC who had undergone molecular testing for both ALK gene rearrangement and EGFR mutation. The clinical features and CT findings of the main lesion and associated pulmonary abnormalities were investigated. RESULTS: Female gender (P = 0.0043 vs. non‐ALK/EGFR), young age (P = 0.0156 vs. EGFR), and a light or never smoking history (P = 0.0039 vs. non‐ALK/EGFR) were significant clinical characteristics of NSCLC with ALK gene rearrangement. The significant CT characteristics compared to NSCLC with EGFR mutation were a large mass (P = 0.0155), solid mass (P = 0.0048), and no air bronchogram (P = 0.0148). A central location (P = 0.0322) and lymphadenopathy (P = 0.0353) were also more frequently observed. Coexisting emphysema was significantly less frequent in NSCLC patients with ALK gene rearrangement (P = 0.0135) than non‐ALK/EGFR. CONCLUSIONS: NSCLC with ALK gene rearrangement was more likely to develop in younger women with a light or never smoking history. The characteristic CT findings of NSCLC with ALK gene rearrangement were a large solid mass, less air bronchogram, a central location, and lymphadenopathy.