ESTRO 2025 - Abstract Book

S4422

Late-breaking abstracts

ESTRO 2025

Results 592 patients were enrolled between 2016-2021, of whom 564 were eligible and evaluable. Median age was 69 years, and median follow-up was 58.1 months. 367 were randomised to the molecular-profile-arm and 197 to the VBT-arm. In the molecular-profile-arm, adjuvant treatment was omitted in 46% of patients, 40% received VBT, and 14% EBRT, while in the standard arm 100% received VBT. 5-year cumulative incidence of VR was 4.5% in molecular-profile-arm vs 1.6% in VBT-arm (HR=2.72(95%CI 0.37-9.36)). The difference of the one-sided 95%CI between the arms was estimated at 5.3%, below the predefined equivalence margin of 7% ( p non-inferiority =0.005). PR were slightly less frequent in the molecular-profile-arm: 3.2% vs. 5.2% in the VBT-arm ( p =0.32). LRR was 8.8% vs. 7.5% ( p =0.62). RFS and OS did not differ: RFS 81.7% vs. 85.1% ( p= 0.36), and OS 88.0% vs. 90.9%( p =0.34). Subgroup analysis in patients with a favourable profile showed 5-year cumulative incidence of VR of 4.7% vs. 0.9% (HR=4.61, 95%CI 0.57-37.5), below the predefined equivalence margin of 8.5% ( p non-inferiority =0.02). Exploratory analysis in patients with an unfavourable profile subgroup showed a 5-year cumulative incidence of LRR of 8.4% vs. 30.5% (p=0.05) and DM of 22.3% vs 41.8%(p=0.47).