Distinct Clinicopathologic Characteristics and Prognosis Based on the Presence of Ground Glass Opacity Component in Clinical Stage IA Lung Adenocarcinoma

Abstract

Introduction

We evaluated differences in the clinicopathologic characteristics and prognosis based on the presence of ground glass opacity (GGO) components in small-sized lung adenocarcinoma.

Methods

We retrospectively investigated 634 lung adenocarcinomas classed as c-stage IA in the eighth edition TNM classification. Staging was defined according to the solid component size measured by thin-section computed tomography. All tumors were grouped into either a GGO or solid group, based on the presence of a GGO component.

Results

Of the cases, 215 (34%) were classed as c-stage IA1 (T1mi: 88, T1a-GGO: 102, T1a-solid: 25), 255 (40%) as c-stage IA2 (T1b-GGO: 122, T1b-solid: 133), and 164 (26%) as c-stage IA3 (T1c-GGO: 44, T1c-solid: 120). Among the 546 c-stage IA cases excluding the T1mi lesions, Cox regression analysis revealed that presence of GGO was an independently significant prognosticator (p = 0.024). The result was validated in 494 c-stage IA lung adenocarcinomas with a nonpredominant GGO component, showing the presence of GGO as a significant prognosticator (p = 0.048). When we evaluated the prognostic impact of GGO presence in each clinical stage, the 5-year overall survival (OS) was significantly different between the GGO and solid groups (IA1: 97.8% versus 86.6%, p = 0.026; IA2: 89.3% versus 75.2%, p = 0.007; IA3: 88.5% versus 62.3%, p = 0.003). Furthermore, the 5-year overall survival b was distinct in parallel similar pathologic findings when comparing a lepidic versus an invasive component (IA1: 97.9% versus 85.6%, p = 0.031; IA2: 86.1% versus 69.4%, p = 0.007; IA3: 77.5% versus 55.8%, p < 0.001).

Conclusions

Clinicopathologic and oncologic outcomes were disparate based on the presence of a GGO component in the eighth edition TNM classification of c-stage IA lung adenocarcinoma.