A modified T categorization for part-solid lesions in Chinese patients with clinical stage I Non-small cell lung cancer

Abstract

Objectives: We evaluated the prognostic impact of the presence of ground glass opacity (GGO) component and compared a modified clinical T categorization (cT_m) with the current 8th classification (cT₈) for survival prediction in Chinese patients with clinical stage I non-small cell lung cancer (NSCLC).

Methods: According to cT_m and cT₈ classifications, we retrospectively evaluated 1461 patients with part-solid or pure-solid lesions. The recurrence-free survival (RFS) and overall survival (OS) were analyzed by Kaplan-Meier method and Cox proportional hazard model. The concordance index (C- index), reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA) were performed to estimate reclassification net benefits of cT_m for survival prediction.

Results: The cT₈ classification clearly stratifies the survival outcomes in solid tumors but not in part-solid tumors. The presence of GGO components was an independent prognostic factor for both RFS and OS (p < 0.001), indicating a better outcome in each clinical T stage. The C-index was significantly improved from 0.650 to 0.730 for RFS (p < 0.001) and 0.647 to 0.730 for OS (p < 0.001) after reclassifying by cT_m categorization. The DCA, NRI (RFS: 0.342, OS: 0.302), and IDI (RFS: 0.070, OS: 0.054) demonstrated that the cT_m classification provided more net benefit in the survival prediction compared with the current cT₈ classification.

Conclusions: The current cT₈ classification may not be appropriate for part-solid lesions because the presence of GGO components is associated with excellent prognosis despite clinical stage. Also, the cT_m classification for part-solid lesions showed an improvement in survival prediction.

Keywords: Ground glass opacity; Non–small cell lung cancer; Survival.