Optimised architecture-based grading system as an independent prognostic factor in resected lung adenocarcinoma.

Aims: Considering morphological heterogeneity of lung adenocarcinoma (LUAD) and no objective prognostic grading system existing currently, we aim to establish an 'optimised architecture-based grading system' (OAGS) to predict prognosis for resected LUAD.

Methods: A multicentral study involving three independent cohorts of LUAD was conducted. Predictive ability of the OAGS for recurrence-free probability (RFP) and overall survival (OS) was assessed in training cohort (n=228) by the area under the receiver operating characteristic curve (AUC), Harrell's concordance index (-index) and Kaplan-Meier survival analyses, which was validated in testing (n=135) and validation (n=226) cohorts.