Prognostic factors of lung adenocarcinoma manifesting as ground glass nodules larger than 3 cm.

OBJECTIVES The aim of the study was to investigate prognostic factors of lung adenocarcinomas manifesting as ground glass nodules larger than 3cm 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 3cm 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 62months. The median values of the whole size and the solid size were 3.5cm and 2.3cm, respectively. The 3-year and 5-year OS rates were 95.5% and 86.2%, respectively. Patients with lesions <2.3cm had markedly better OS than those with lesions >= 2.3cm. No significant differences existed between the survival of patients with lesions <3.5cm and >= 3.5cm. 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 3cm. Clinical T staging should be based on the solid size rather than on the whole size of these lesions.