Impact of ground glass opacity in a three-dimensional analysis for pathological findings and prognosis in stage IA pure solid lung cancer

Abstract

Background: We investigated whether a three-dimensional (3D) analysis could correct the discrepancy between conventional computed tomography findings and pathological findings and contribute to prognostic stratification in early pure solid lung cancer.

Methods: A total of 370 patients with two-dimensional (2D) pure solid, clinical stage IA non-small cell lung cancer (NSCLC) who underwent complete resection at our hospital between January 2010 and March 2021 were included in the present study. We classified the patients into the 3D solid group and the 3D ground glass opacity (GGO) group according to the consolidation volume/tumor volume ratio (C/T volume ratio) measured using a Synapse Vincent 3D analysis workstation, and compared the pathological findings and prognosis between the two groups.

Results: There were 142 (38.4%) patients in the 3D GGO group. Lepidic lesions were significantly more frequent in the 3D GGO group (27.6% vs. 59.2%, P<0.001). Lymphatic invasion, vascular invasion and lymph node metastasis were significantly more frequent in the 3D solid group (52.2% vs. 27.5%, P<0.001; 67.5% vs. 43.0%, P<0.001; 22.3% vs. 11.2%, P=0.04). A Cox proportional hazards multivariate analysis for overall survival (OS) and recurrence-free survival (RFS) showed that 3D solid was an independent poor prognostic factor [hazard ratio (HR): 1.981, P=0.02; HR: 1.815, P=0.02]. Kaplan-Meier curves for 5-year OS (74.1% vs. 87.8%, P<0.001) and 5-year RFS (65.6% vs. 84.9%, P<0.001) showed significant differences between the two groups.

Conclusions: The C/T volume ratio determined by a 3D analysis detects GGO and reflects the pathological findings, and further prognostic stratification is possible in early 2D pure solid lung cancer.

Keywords: Lung cancer; Synapse Vincent; clinical stage IA; consolidation volume/tumor volume ratio (C/T volume ratio); ground-glass opacity.

Figure 1

The consort diagram of the current study. A total of 370 patients with clinical stage IA NSCLC who were judged to be pure solid on 2D CT and who did not meet the exclusion criteria were enrolled in this study. After measuring the C/T volume ratio, 228 cases with a C/T volume ratio of ≥0.9 were classified into the 3D solid group, and 142 cases with a C/T volume ratio of <0.9 were classified into the 3D GGO group. In the 3D analysis image, purple indicates the solid component and green indicates the GGO component. NSCLC, non-small cell lung cancer; PET, positron emission tomography; CT, computed tomography; C/T ratio, consolidation to tumor ratio; GGO, ground glass tumor; 2D, two-dimensional; 3D, three-dimensional.

Figure 2

Kaplan-Meier curves showing the survival outcomes of the two groups. The significant differences in OS (A) and RFS (B) were observed between the two groups. OS, overall survival; RFS, recurrence-free survival; GGO, ground glass tumor.

Figure 3

Kaplan-Meier curves showing the survival outcomes of the two propensity score matched groups. Significant differences were observed between the two groups in OS (A) and RFS (B), as was observed before propensity score matching. Consistently, the 3D GGO group showed a better prognosis than the 3D solid group. OS, overall survival; RFS, recurrence-free survival; GGO, ground glass tumor; 3D, three-dimensional.