Distinct Prognostic Factors in Patients with Stage I Non–Small Cell Lung Cancer with Radiologic Part-Solid or Solid Lesions

IntroductionRecent studies have indicated that the presence of ground-glass opacity (GGO) components is associated with favorable survival. The purpose of this study was to reveal the prognostic value of GGO components and differences in prognostic factors for part-solid and solid lesions in invasive stage I NSCLC.MethodsThe cases of 2010 patients with completely resected invasive pathological stage I NSCLC were reviewed according to the eighth edition of the TNM classification. Patients were categorized into the pure-GGO, part-solid, and solid groups based on consolidation-to-tumor ratio. Cox multivariate proportional hazard analyses were conducted to identify independent prognostic factors in each group.ResultsOf the 2010 patients, 146 (7.3%) were in the pure-GGO group, 732 (36.4%) were in the part-solid group, and 1132 (56.3%) were in the solid group. Cox multivariate analyses revealed that GGO absence was a strong independent risk factor for worse recurrence-free survival (p < 0.001). For the pure-GGO group, there was no recurrence in spite of the invasive stage. For the part-solid group, visceral pleural invasion could not predict recurrence-free survival in general (p = 0.514) or in each tumor size group (for tumors size ≤1 cm, p = 0.664; for tumors size >1 to 2 cm, p = 0.456; for tumors size >2 to 3 cm, p = 0.900; and for tumors size >3 to 4 cm, p = 0.397). For the solid group, adenocarcinoma subtype was not a prognostic factor for recurrence-free survival in general (p = 0.162) or in each tumor size group (for tumors size ≤ 2 cm, p = 0.092; for tumors size >2 to 3 cm, p = 0.330; and for tumors size >3 to 4 cm, p = 0.885).ConclusionsThe presence of GGO components was a strong predictor in patients with invasive pathological stage I NSCLC. Risk factors were distinct in the part-solid and solid groups. There was no prognostic value of visceral pleural invasion in the part-solid group. Adenocarcinoma subtype did not have prognostic value in the solid group.