Reappraising the clinical usability of consolidation-to-tumor ratio on CT in clinical stage IA lung cancer
Dong Woog Yoon, Chu Hyun Kim, Soohyun Hwang, Yoon‐La Choi, Jong Ho Cho, Hong Kwan Kim, Yong Soo Choi, Jhingook Kim, Young Mog Shim, Sumin Shin, Ho Yun Lee
Abstract
OBJECTIVES: Ground-glass opacity (GGO) on computed tomography is associated with prognosis in early-stage non-small cell lung cancer (NSCLC) patients. However, the stratification of the prognostic value of GGO is controversial. We aimed to evaluate clinicopathologic characteristics of early-stage NSCLC based on the consolidation-to-tumor ratio (CTR), conduct multi-pronged analysis, and stratify prognosis accordingly. METHODS: We retrospectively investigated 944 patients with clinical stage IA NSCLC, who underwent curative-intent lung resection between August 2018 and January 2020. The CTR was measured and used to categorize patients into six groups (1, 0%; 2, 0-25%; 3, 25-50%; 4, 50-75%; 5, 75-100%; and 6, 100%). RESULTS: Pathologic nodal upstaging was found in 1.8% (group 4), 9.0% (group 5), and 17.4% (group 6), respectively. The proportion of patients with a high grade of tumor-infiltrating lymphocytes tended to decrease as the CTR increased. In a subtype analysis of patients with adenocarcinoma, all of the patients with predominant micro-papillary patterns were in the CTR > 50% groups, and most of the patients with predominant solid patterns were in group 6 (47/50, 94%). The multivariate analysis demonstrated that CTR 75-100% (hazard ratio [HR], 3.85; 95% confidence interval [CI], 1.58-9.36) and CTR 100% (HR, 5.58; 95% CI, 2.45-12.72) were independent prognostic factors for DFS, regardless of tumor size. CONCLUSION: We demonstrated that the CTR could provide various noninvasive clinicopathological information. A CTR of more than 75% is the factor associated with a poor prognosis and should be considered when making therapeutic plans for patients with early-stage NSCLC.