Prognostic impact of ground-glass opacity components in lung cancer with lymph node metastasis

In early-stage non-small cell lung cancer (NSCLC), the presence of a ground-glass opacity (GGO) component in the primary lesion on high-resolution computed tomography (CT) is recognized as a favorable prognostic factor. Even in NSCLC with a GGO component, lymph node metastases are occasionally detected during or after surgery. However, the prognostic impact of GGO components in these patients has not been clarified. We aimed to examine the prognostic significance of GGO components as radiological findings of primary lesions of completely resected NSCLC with pathological nodal involvement.

This study included 290 patients (11%) with pathological nodal involvement among 2,546 patients who underwent complete resection of NSCLC at our institution. Patients with an unknown primary lesion (T0) or centrally located lung cancer were excluded. The 290 patients were divided into two groups [i.e., the part-solid ("PS") and "Solid" groups] according to the radiological findings of the primary lesion, and their clinicopathological characteristics and prognoses were compared. Furthermore, a multivariate analysis was performed using the Cox proportional hazards model to examine the factors affecting the overall survival (OS).

The OS in the PS group (n=58) was significantly longer than that in the Solid group (n=232; P=0.039). However, multivariate analysis only revealed age [hazard ratio (HR) =1.77; 95% confidence interval (CI): 1.15-2.72] and the clinical T factor (HR =1.58; 95% CI: 1.01-2.47), but not the radiological findings of primary lesions, as the independent prognostic factors. Furthermore, the OS did not differ significantly between the PS and Solid groups matched for the clinical T and N factors (n=58 patients each).

GGO components in the primary lesion, considered a decisive prognostic factor in early-stage NSCLC, did not affect the prognosis of patients with NSCLC and pathological nodal involvement.