Objectives: The aim of the study was to investigate prognostic factors of lung adenocarcinomas manifesting as ground glass nodules larger than 3 cm on thin-section computed tomography scans, especially comparing the prognostic role of the whole size and the solid size.
Methods: We included 195 patients with lung adenocarcinomas manifesting as ground glass nodules larger than 3 cm who underwent surgical resection. We identified clinical factors associated with lymph node metastases by binary logistics regression analysis. Kaplan-Meier analysis was performed to determine the association between the whole size or the solid size and overall survival (OS). Multivariable Cox regression analysis was used to identify prognostic factors of OS.
Results: The median follow-up time was 62 months. The median values of the whole size and the solid size were 3.5 cm and 2.3 cm, respectively. The 3-year and 5-year OS rates were 95.5% and 86.2%, respectively. Patients with lesions <2.3 cm had markedly better OS than those with lesions ≥2.3 cm. No significant differences existed between the survival of patients with lesions <3.5 cm and ≥3.5 cm. Multivariable analysis showed that bigger solid size was significantly associated with the presence of lymph node metastases and inferior OS, whereas larger whole size was not. Adjuvant chemotherapy improved the OS of patients with stage Ib and II-IIIa disease, but not that of patients with stage Ia disease.
Conclusions: Solid size was a better predictor of lymph node metastases and prognosis than whole size in ground glass nodules larger than 3 cm. Clinical T staging should be based on the solid size rather than on the whole size of these lesions.
Keywords: Ground glass nodules; Solid size; Whole size.
© The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.