Tumor Mass Is a Better Prognostic Factor Than Consolidation-to-Tumor Ratio in Invasive Lung Adenocarcinoma Manifest Difficult-to-Measure Solid Portion.

Objectives: To evaluate the long-term prognosis and related factors in patients who manifest part-solid invasive lung adenocarcinoma with difficult-to-measure solid portions. Methods: Patients with resected clinical stage I part-solid invasive lung adenocarcinoma in a single institution were retrospectively enrolled. They were divided into measurable and difficult-to-measure groups according to whether the radiologically solid portion was difficult to measure. The Kaplan-Meier method was used to evaluate the outcomes. Cox analysis was used to explore the prognostic factors. Tumor nodules were segmented using 3D Slicer software to extract quantitative features. Results: Of the 1240 patients, 225 (18.2%) were classified into the difficult-to-measure group. The intraclass correlation coefficient revealed that two readers had an excellent agreement on solid size in the measurable group (0.88), but not in the difficult-to-measure group (0.65). Compared with the measurable group, these tumors were larger and exhibited comparable overall survival (10 y 95.0% versus 94.2%; Conclusions: Patients with invasive adenocarcinoma manifesting as part-solid nodules whose solid components were difficult to measure revealed favorable outcomes. Tumor mass was a better prognostic indicator than consolidation-to-tumor ratio for this population.