Oncological Characteristics of Radiological Invasive Adenocarcinoma with Additional Ground-Glass Nodules on Initial Thin-Section Computed Tomography: Comparison with Solitary Invasive Adenocarcinoma

Abstract

IntroductionWe aimed to evaluate the oncological outcomes of radiological invasive adenocarcinoma with additional ground-glass nodules (AGGNs) on initial thin-section computed tomography (CT). MethodsWe examined 473 patients with surgically resected clinical stage IA lung adenocarcinoma showing a radiological invasive appearance on thin-section CT. Radiological invasiveness was defined as a solid tumor with a consolidation tumor ratio of at least 0.5 but no greater than 1.0 on thin-section CT. ResultsNinety patients (19%) had dominant invasive adenocarcinoma (DA) with AGGNs, whereas 383 (81%) had solitary invasive adenocarcinoma (SA). DA showed a significantly lower maximum standardized uptake value of 18F-fluorodeoxyglucose on positron emission tomography (p = 0.0086), higher frequency of radiological part solid tumor (p = 0.0232) and histological lepidic predominant tumor (p = 0.0015), and lesser presence of nodal involvement (p = 0.0350) and lymphovascular invasion (p = 0.0001) than with SA. Surgically resected AGGNs were shown to be pathologically atypical adenomatous hyperplasia in 17% of patients, adenocarcinoma in situ in 53%, and minimally invasive adenocarcinoma in 21%. Furthermore, the 5-year overall survival of DA with AGGNs was better than that of SA, and the difference was significant (92.2% versus 79.9%, p = 0.0323). On the basis of a multivariate analysis, tumor size, maximum standardized uptake value, and consolidation status of DA/SA were significant prognostic factors of survival for all patients (p = 0.0039, 0.0236, and 0.0385, respectively), whereas the presence of AGGNs was not associated with poor overall survival (p = 0.4809). ConclusionDA accompanied by AGGNs showed an oncologically less invasive nature compared with SA. Presence of AGGNs is not related to poor prognosis, and is neither indicative of an advanced stage nor a contraindication to surgical resection in patients with clinical stage IA radiological invasive adenocarcinoma.