75P Locally advanced, stage III non-small cell lung cancer: A highly heterogenous patient population

Background: Non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancers and is often diagnosed at an advanced stage. Locally advanced stage III NSCLC represents a highly heterogenous group of patients; treatment poses a challenge, as an accurate evaluation and staging must occur to ensure the selection of an optimal management. Our goal was to characterize a cohort of patients diagnosed with stage III NSCLC, concerning disease characteristics and treatment procedures. Methods: Real-world retrospective cohort study, including patients diagnosed with locally advanced stage III NSCLC between January 1st, 2017 and April 30th, 2018 in a Portuguese Comprehensive Cancer Center (PCCC). Data, collected from medical/administrative records, covered demographics, tumor histology, TNM staging, ECOG performance status, surgical resection, EGFR status, PD-L1 expression, treatment and outcomes. Descriptive statistics analysis was conducted for demographic, clinical and resource utilization data. The Kaplan-Meier method was used for survival analysis. Results: 92 patients were included. Only 18.5% (n = 17) had resectable disease. Before surgery, 29.4% (n = 5) of the patients received neoadjuvant treatment. 81.5% (n = 75) had unresectable disease, and over one third (37.3%) received either concurrent (17.9%; n = 5) or sequential (82.1%; n = 23) chemoradiotherapy (CRT). Tumor histology of patients who received CRT was adenocarcinoma (n = 14) or squamous-cell carcinoma (n = 14). 57.1% (n = 16) of patients had partial response to treatment, 21.4% (n = 6) had stable disease, and disease progression was found in 14.3% (n = 4) of patients. Those who did not receive CRT were mostly treated only with systemic anti-cancer therapy (SACT) (66%; n = 31). The median overall survival of stage III NSCLC was patients was 19.4 months (95%CI 13.9 – NA). Conclusions: Advanced stage III NSCLC is incompatible with a unique schematic treatment approach. Multiple therapeutic strategies are employed as a result of the high variability in tumor extent and nodal involvement. Further research on molecular and immunological characterization is required to better define targeted and effective approaches, with improved outcomes. Legal entity responsible for the study: AstraZeneca Portugal. Funding: AstraZeneca Portugal. Disclosure: F. Bernardo: Full/Part-time employment: AstraZeneca. S. Figueiredo: Full/Part-time employment: AstraZeneca. All other authors have declared no conflicts of interest.