ESTRO 2025 - Abstract Book

S1699

Clinical - Sarcoma & skin cancer & malignant melanoma

ESTRO 2025

Conclusion: Our preliminary experience suggest that the association of Cemiplimab and RT is safe and effective for patients with a good toxicity profile and a significant tumor response. Kurian J et al published in literature another similar clinical experience about 7 patients with similar conclusion about integration of RT and Cemiplimab. Data in-vitro suggested that PD-1 inhibitor may improved response to radiotherapy and probably in the future we could have indication of more tailored RT schedules and doses. Further literature data are needed but Cemiplimab and RT may become a viable therapeutic options for these setting of patients.

Keywords: cemiplimab radiotherapy skin squamous cell cancer

References: Joseph K, Walker J, Raziee H, Faruqi S, Smylie M. PD-1 Blockade With Concurrent Radiotherapy for Locally Advanced Inoperable Cutaneous Squamous Cell Carcinoma. J Cutan Med Surg. 2022 May-Jun;26(3):243-248. doi: 10.1177/12034754211064273. Epub 2021 Dec 4. PMID: 34866423.

2906

Poster Discussion Comparative analysis of local efficacy of radiotherapy for oligoprogression in metastatic melanoma with or without locoregional hyperthermia Aneta Maria Borkowska 1,2 , Paulina Chmiel 1 , Piotr Rutkowski 1 , Maria Telejko 2 , Mateusz Jacek Spałek 2,1 1 Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland. 2 Department of Radiotherapy I, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland Purpose/Objective: To compare the local outcomes and safety of radiotherapy (RTH) vs RTH combined with hyperthermia (HT) in metastatic melanoma (MM). Material/Methods: Patients with oligoprogressive MM treated with RTH+HT at a melanoma center between 2019 and 2023 were included. Oligoprogression was defined as up to 5 progressive metastases. The inclusion criteria were the availability of follow-up imaging after radiotherapy and concomitant systemic therapy. The comparison of RTH vs RTH+HT was evaluated in terms of local control (LC) which was defined as the percentage of patients who met the RECIST1.1 criteria for stable disease (SD), partial response (PR), and complete response (CR) and local benefit (LB) was defined as the percentage of patients who met the RECIST1.1 criteria for PR and CR. Results: The 156 patients were included in the study, 82 pts had RT+HT while 74 RTH only. Median follow-up was 17.5 months (12.7-21.4 m). Most patients (82.7%) were irradiated during immunotherapy (ITH), and 17.3% during BRAF/MEK inhibitors. Median LC was not reached at the time of analysis in both groups. The 1- and 2-year LC rates for the RTH group were 92.8% and 91%, respectively. While in the RTH+HT group were 94.6% and 87.5%, respectively. Median LB was not reached at the time of analysis in both groups. The 1- and 2-year LB rates for the RTH group were 80.7% and 77%, respectively. While in the RTH+HT group were 88.7% and 78.2%, respectively. No statistically significant differences were observed between the study groups for either the LC (p = 0.99) or the LB (p = 0.48). 41 pts (26.3%) patients experienced an increase, relapse, or new AEs within 1 month of RTH+HT, which were considered a direct effect of treatment, among which 18 pts (11.5%) had RTH+HT. Of these, 13 (8.3%) had AEs ≥ grade 3 according to CTCAE 5.0.