121P Treatment of unresectable stage III NSCLC: Real-world study and literature review

Abstract

The standard treatment of unresectable stage III non-small cell lung cancer (NSCLC) is combined chemoradiotherapy (CRT), delivered either concurrently (cCRT) or sequentially (sCRT). There is, however, limited data on the outcomes and safety of CRT in real-world setting. We performed an analysis of the Leuven Lung Cancer Group (LLCG) experience with CRT for unresectable stage III NSCLC prior to the era of consolidation treatment with immunotherapy. We conducted a retrospective, monocentric cohort study at the university hospital UZ Leuven, Belgium, and retrieved 163 consecutive patients who were treated with CRT for unresectable stage III NSCLC between January 1st 2011 and December 31st 2018. Patient and tumor characteristics, treatment patterns, toxicity, and primary outcome parameters were analyzed. Chemotherapy was given concurrently in 108 patients, sequentially in 55. Overall tolerability was good with two thirds of patients having no severe adverse events: severe febrile neutropenia (9,2%), ³ grade 2 pneumonitis (16%), or ³ grade 3 esophagitis (19%). Adverse events were more frequent in the cCRT than sCRT group. Median PFS was 13.2 months (95% CI 10.3-16.2). In the patients with progressive disease, the site of first progression was locoregional in 36% and distant in 64%, with no significant difference between cCRT and sCRT. Median OS was 23.3 months (95% CI 18.3-28.0), with a 47.5% survival rate at 2 years and 29.4% at 5 years. In multivariate Cox regression analysis, Karnofsky performance status, stage (UICC TNM 8th edition) and COPD were significant factors for OS, while sequence of therapy (cCRT versus sCRT) lost significance in multivariate testing. Our real-world PFS, OS and toxicity results are comparable to those reported in randomized controlled trials (RTOG 0617, PROCLAIM). Sequence of therapy did not independently associate with OS, likely since the choice for a sequential versus concurrent approach is strongly influenced by other main drivers of survival such as performance status. This study provides a clinically relevant real-world benchmark on the outcomes of cCRT and sCRT before the start of the immunotherapy era in this setting.