264P BE-LUNG: Multicenter real-world biomarker status, treatments, and overall survival in early NSCLC Belgian patients

Background: Recurrence after complete (R0) resection remains a major clinical challenge in non-small cell lung cancer (NSCLC).This study aimed to describe the timing and risk of recurrence following curative R0 resection, explore clinicopathological predictors, and examine whether recurrence dynamics could guide postoperative surveillance.Methods: This observational analysis used data from the prospective Thoracic Tumour Registry (TTR) of the Spanish Lung Cancer Group.We included a prospectively monitored cohort of patients with pathological stage I-IIIA NSCLC who underwent R0 resection without neoadjuvant therapy.Recurrence-free survival (RFS) was estimated using Kaplan-Meier analysis, and recurrence hazard was modelled with spline-based smoothing (bshazard).Clinicopathological factors were assessed using Cox models.Results: Of 3,927 eligible patients, 3,819 had valid follow-up.Median RFS was 37.7 months, with the highest recurrence hazard observed at 10.3 months after-surgery.Women exhibited longer RFS and later hazard peaks than men, and higher pathological stage was associated with progressively shorter RFS and increased recurrence risk.While the timing of hazard peaks was similar across all recurrence patterns, patients with distant relapses experienced higher overall recurrence risk (HR 1.46, p = 0.005).N-stage distribution varied significantly across progression patterns (p < 0.001). Conclusions:In this Spanish cohort, recurrence risk was highest during the first postoperative year and varied by sex, stage, recurrence pattern and stage.These findings support the need for personalised surveillance strategies based on subgroup-specific recurrence dynamics and, to our knowledge, provide one of the largest real-world analyses of recurrence patterns in resected NSCLC in Europe.Clinical trial identification: NCT02941458.