Differences in the prognostic implication of ground-glass opacity on CT according to pathological nodal status in lung cancers treated with lobectomy or pneumonectomy

Abstract

Objectives: To clarify the prognostic significance of a ground-glass opacity (GGO) component according to T category and pathological nodal status in patients with resectable non-small cell lung cancer (NSCLC).

Methods: Patients who underwent lobectomy or pneumonectomy for NSCLC between July 2010 and December 2017 were retrospectively included. Patients were divided into GGO and solid groups based on the presence of a GGO component on CT. The effects on survival of interactions between GGO and (a) pathological nodal status (pN) and (b) cT category were evaluated using Cox regression.

Results: Out of 1545 patients, 548 were classified into the GGO group (pN0: 457, pN1/2: 91) and 997 into the solid group (pN0: 660, pN1/2: 337). There were interactions between the presence of GGO and pathological nodal status on 5-year disease-free survival (DFS; p = .006) and 5-year overall survival (OS; p = .02). In multivariate analysis, better survival of patients in the GGO group than in the solid group was observed only in pN0 category (adjusted hazard ratio [HR], 0.63 for 5-year DFS; p = .002 and 0.47 for 5-year OS; p = .002), but not in pN1/2 category. Moreover, in those with pN0 category, the favorable prognostic value of GGO was limited to those with cT1 category for 5-year DFS (adjusted HR, 0.48; p < .001) and those with cT1/2 category for 5-year OS (adjusted HR, 0.37; p = .002).

Conclusions: GGO was a favorable predictor of survival only in patients with pN0 category, showing an advantage in DFS for those with cT1 category and OS for those with cT1/2 category.