Introduction: Precise pre-treatment staging of non-small cell lung cancer (NSCLC) determines initial treatment and provides more accurate prognostic information for patients.

Aim: To determine the agreement between clinical and pathological stage for patients with NSCLC, and its effect on 2-year survival in a cohort of patients who had modern staging investigations.

Methods: Patient data were prospectively collected from 11 local MDTs. We included consecutive patients in the West of Scotland who underwent surgical resection from 2015 to 2017. Clinical and pathological TNM stages were recorded and compared and we investigated the effect of stage change on survival.

Results: 975 patients had a complete data and fulfilled the inclusion criteria. 55% were female and the mean age was 69. Concordance between clinical and pathological TNM was achieved in 558 (57%) patients, 280 (29%) were pathologically upstaged, and 137 (14%) downstaged after surgery. 124 patients (13%) had a higher pathological N stage, of which 70 (56%) had unforeseen N2 or N3 disease. Patients who were pathologically upstaged had poorer survival(Figure 1, p< 0.0001).However, this difference was explained by pathological stage.

Conclusions: Accuracy of pre-operative NSCLC staging is poor despite the widespread availability of PET-CT and endobronchial ultrasound. Improvement in pre-operative staging is necessary to ensure the correct first treatment is delivered to patients.