Consolidation-to-tumor ratio and tumor disappearance ratio are not independent prognostic factors for the patients with resected lung adenocarcinomas

Abstract

Objectives: Our study aimed to investigate the independent prognostic values of consolidation-to-tumor ratio (CTR) and tumor disappearance ratio (TDR) after adjustment for the conventional prognostic factors and the eighth edition clinical T category for patients with resected lung adenocarcinomas.

Materials and methods: This retrospective study included 691 patients (281 men and 410 women; median age, 63 years) with resected lung adenocarcinomas (clinical T1N0M0). The prognostic implications for disease-free survival (DFS) of CTR and TDR in continuous and categorical forms were analyzed using multivariable-adjusted Cox regression analysis, including multiple clinico-radiological prognostic factors and the clinical T category based on the solid portion measurement. Analysis was performed for the total study population and for two part-solid nodule subgroups (cT1mi/cT1a to cT1c and cT1mi/cT1a to cT1b, respectively).

Results: For the total study population, CTR and TDR were not selected in the multivariable Cox regression models, which indicated that these are not independent prognostic factors. Age (adjusted HR: 1.026; P = 0.022) and clinical T category (adjusted HR for cT1b: 3.475; P = 0.019; adjusted HR for cT1c: 9.938; P < 0.001) were independently associated with DFS. For the part-solid nodule subgroups, multivariable-adjusted HRs for CTR and TDR were not statistically significant (all P > 0.05).

Conclusion: CTR and TDR were not independent prognostic factors. Preoperative prognostication based on clinical T category would be sufficient without further stratification according to CTR or TDR.

Keywords: Adenocarcinoma; Consolidation-to-tumor ratio; Disease-free survival; Neoplasm staging; T category; Tumor disappearance ratio.