Ground-Glass Opacity Is a Strong Prognosticator for Pathologic Stage IA Lung Adenocarcinoma

Abstract

A ground-glass opacity (GGO) component on chest computed tomography (CT) pathologically corresponds to lepidic adenocarcinoma. However, the precise correspondence relation and the prognostic significance remains unclear in patients with pathologic stage IA lung adenocarcinoma. We retrospectively reviewed the clinicopathologic features of 809 consecutive patients with pathologic stage IA lung adenocarcinoma who underwent complete resection between 2003 and 2014. We evaluated the prognostic impact of clinicopathologic variables including the radiologic appearance with a Cox proportional hazards model. Among the 809 patients, 465 (57%) were nodules with a GGO component, and 344 (43%) were solid nodules on chest CT. On final pathology, lepidic adenocarcinoma was identified in 445 (96%) of the GGO nodules and 239 (69%) of the solid nodules. The survival rate of the patients having a GGO nodule was significantly higher than that without GGO components (5-year overall survival, 97% versus 84%, p < 0.0001). In solid nodules, there was no significant prognostic difference between patients with and without a lepidic component (5-year overall survival, 87% versus 79%, p= 0.09). On multivariable analysis, solid appearance on chest CT was an independent prognostic factor (hazard ratio, 1.74; 95% confidence interval, 1.10 to 2.79; p= 0.019), but the pathologic invasive size and the pathologic lepidic growth component were not. In patients with pathologic stage IA lung adenocarcinoma, the radiologic appearance as a GGO nodule on chest CT is a better prognostic indicator than the presence of a lepidic component on pathology.