Role of ground-glass opacity in pure invasive and lepidic component in pure solid lung adenocarcinoma for predicting aggressiveness

OBJECTIVE: Lung adenocarcinoma often includes noninvasive components with postoperative lepidic morphology on pathologic specimens that appear on preoperative high-resolution computed tomography (HRCT) images as ground-glass opacity (GGO). We aimed to disclose the role of GGO on the aggressiveness of pathologically confirmed pure invasive tumors in patients with early-stage lung adenocarcinoma. METHODS: The prognosis of 932 patients with clinical stage 0-IA and pathologic node-negative lung adenocarcinoma who underwent lobectomy at 3 institutions between 2010 and 2016 was investigated according to the status of GGO and lepidic components. RESULTS: The recurrence-free survival (RFS) of patients with pathologically confirmed pure invasive tumors was worse without (n = 81) than with (n = 43) GGO (69.7%; 95% confidence interval [CI], 57.3%-79.2% vs 90.5%; 95% CI, 76.6%-96.3%, P = .028). The RFS of patients with radiologically confirmed pure solid tumors was worse without (n = 81), than with (n = 173) a lepidic component (69.7%; 95% CI, 57.3%-79.2% vs 85.3%; 95% CI, 77.2%-90.7%, P = .0012). Multivariable Cox regression analysis of overall survival and RFS revealed that pure solid and pure invasive tumors, respectively, determined by HRCT and pathologic assessment together comprised an independent prognostic factor like vascular or pleural invasion for patients with early-stage lung adenocarcinoma. CONCLUSIONS: Tumors of non–small cell lung cancer with pure solid and pure invasive components were more aggressive than those with some GGO and lepidic components. Complementary HRCT and pathologic findings can predict the malignant aggressiveness of adenocarcinoma.