Pathological and radiological T descriptors in invasive lung adenocarcinoma: from correlations to prognostic significance.

ABSTRACT

Background: The eighth T classification excluded lepidic and ground-glass opacity (GGO) components. Current studies demonstrated lepidic and GGO components showed independent prognostic significances. This study elucidated the correlations and prognostic impacts of pathological and radiological T descriptors in invasive lung adenocarcinoma. Methods: A total of 1,490 patients with invasive lung adenocarcinoma were retrospectively reviewed. Correlation between pathological invasive size (PIS) and radiological solid size (RSS), and lepidic ratio and GGO ratio were comprehensively evaluated. Impacts of these pathological and radiological T descriptors on recurrence-free survival (RFS) were comparatively analyzed. Results: Clinical (c)T-stage was more frequently downstaged than upstaged comparing with the pathological (p)T-stage (28.4% vs. 18.2%). The correlation between PIS and RSS in solid nodule was stronger than that in part-solid nodule (solid R2=0.750 vs. part-solid R2=0.355). Some pathological invasive components except solid component were featured as GGO. Among T1 patients, lepidic absent GGO showed better RFS than lepidic present solid nodule (pT1 P=0.001; cT1 P=0.021). Multivariable analysis revealed GGO ratio was an independent prognostic factor for RFS in T1 invasive lung adenocarcinoma, whereas lepidic ratio was not. Conclusions: Among T1 invasive lung adenocarcinoma, GGO ratio showed independent prognostic value for RFS, regardless of RSS. Meanwhile, lepidic ratio was not an independent RFS factor. GGO component rather than lepidic component should be considered as an additional T descriptor.