ESTRO 2023 - Abstract Book

S374

Sunday 14 May 2023

ESTRO 2023

The data comprised 2196 NSCLC patients (99% stage III) treated in 10 cohorts using different receiving cCRT-ICB regimens. Planned RT schedules were 60-66Gy in 30-33 fractions for 9 cohorts and 69.9Gy in 35 fractions for one cohort. Six and four cohorts respectively received anti-PDL1 and anti-PD1 ICBs. ICB was given concurrently/adjuvantly for 4 cohorts and adjuvantly for 6 cohorts. Intended ICB duration was 24 months for one cohort and 12 months for 9 cohorts. In the meta-regression (Table 2), ICB significantly improved survival relative to cCRT alone, producing an estimated 2-year OS gain of 8.6% (95% CI: 5.3-12.2%, p<0.001). However, ICB drug-type (anti-PDL1 vs anti-PD1), ICB timing (concurrent/adjuvant vs adjuvant alone), RT dose and RT duration were not associated with the OS gains achieved using different ICB regimens. In terms of 2-year OS, intended ICB duration was positively associated with OS (p=0.011), while the fraction of tumour PDL1% >1% (p=0.009) and median age (p<0.001) were negatively associated with OS.