Treatment patterns and prognosis in inoperable stage III NSCLC after concurrent chemoradiotherapy with or without immune checkpoint inhibition: Historical overview.

Abstract

e20578 Background: To investigate the impact of treatment patterns in inoperable stage III NSCLC following concurrent chemoradiotherapy with or without immune checkpoint inhibition (cCRT±ICI). Methods: Patients were stratified by treatment year and divided into three subgroups: A (2011–2014), B (2015–2017) and C (2018–2020). Patient- and treatment-related characteristics regarding to PFS and OS were analyzed. Survival parameters were calculated from the last day of thoracic radiotherapy (TRT). Results: 136 consecutive enrolled patients were included. Median follow-up (FU) was 35.7 months; median age was 66.9 years. All patients completed TRT to a total dose ≥60.0 Gy; Median radiotherapy planning target volume (PTV) was 700 cc (range: 172.5–2293.2). Thirty-six (26%) patients received ICI. Median PFS in subgroups A, B and C was 8.0, 8.2 and 26.3 months (p = 0.007). Median OS was 19.9 months, 23.4 months and not reached in subgroups A, B and C (p < 0.05). In subgroup C, median PFS was 14.2 vs. 26.3 months in patients treated with and without ICI. On multivariate analysis for the entire cohort, PTV > 700cc was a negative prognosticator of PFS (HR: 1.522; p = 0.042) and OS (HR: 2.671; p = 0.001); ICI was a predictor of improved PFS (HR: 0.571; p = 0.071) and longer OS (HR: 0.401; p = 0.062). In the Non-ICI cohort, multivariate analyses revealed PTV > 700cc (HR: 1.630; p = 0.047) and SUVmax > 13.75 (HR: 1.859; p = 0.012) were predictors of reduced PFS; PTV > 700cc (HR: 1.958; p = 0.017), SUVmax > 13.75 (HR: 2.405; p = 0.002) and total lung V20 > 30 (HR: 3.357; p < 0.05) were predictors of longer OS. Conclusions: Regardless of ICI, patients receiving multimodal therapy after 2018 demonstrated improved survival compared to patients treated earlier. Both PTV > 700cc and ICI were predictive for PFS and OS in the entire cohort.