Clinical adjustability of radiological tools in patients with surgically resected cT1N0-staged non-small-cell lung cancer from the long-term survival evaluation

BACKGROUND: Various radiological tools have been introduced to determine the malignancy or prognosis of lung carcinomas. We retrospectively summarized the clinical outcomes to evaluate whether radiological tools such as consolidation-to-tumor ratio (CTR), tumor disappearance ratio (TDR), and mediastinal diameter (MD) are suitable for surgically resected non-small-cell lung cancer (NSCLC). METHODS: This retrospective study included 260 patients (128 men and 132 women; median age, 64 years) with cT1N0-staged NSCLC who underwent thoracotomy. Disease-free survival (DFS) and overall survival (OS) outcomes were analyzed using the Kaplan-Meier method and Cox proportional hazards model. RESULTS: When the adjusted hazard ratios (HRs) with reference to cT1a/1 mi were calculated, significant differences were observed in cT1b and cT1c for DFS (P=0.04 and P<0.01, respectively) and in cT1c for OS (P=0.01). For HRs with reference to CTR (≤0.5), a significant difference was only observed in CTR (>0.5) for DFS (P=0.01). For HRs with reference to TDR (≤25%), significant differences were observed in TDR (>75%) for DFS (P=0.02) and OS (P=0.02). For HRs with reference to MD (≤5 mm), significant differences were observed in 6–20 mm (P=0.04) and >20 mm (P=0.02) for DFS and in >20 mm (P=0.02) for OS. CONCLUSIONS: All radiological tools revealed significant correlations with prognosis in the patients with cT1N0-staged NSCLCs. We recommend the use of MD in a clinical context. However, further investigation of this issue is needed.