ESTRO 2024 - Abstract Book

S1587

Clinical - Lung

ESTRO 2024

Aerts 13 , Alfredo Addeo 14,5 , Anne-Marie Dingemans 13 , Giulia Pasello 15 , Mariano Provencio 16,9 , Karin Ribi 17 , Filippo de Marinis 18 , Nuria Mederos 19,5 , Heidi Roschitzki-Voser 17 , Barbara Ruepp 17 , Roswitha Kammler 17 , Zoi Tsourti 3 , Solange Peters 19 , Rolf A. Stahel 17 , on behalf of the ETOP 14-18 CHESS collaborators 17 1 University Hospital Zurich, University Zürich, Department for Radiation Oncology, Zürich, Switzerland. 2 University Hospital Zurich, Department of Thoracic Surgery, Zürich, Switzerland. 3 Frontier Science Foundation-Hellas, ETOP Statistical Office, Athens, Greece. 4 Hôpital Cantonal HFR Fribourg, University of Fribourg, Department of Oncology, Fribourg, Switzerland. 5 Swiss Group for Clinical Cancer Research, (SAKK), Bern, Switzerland. 6 University Hospital Zurich, Diagnostic and Interventional Radiology, Zürich, Switzerland. 7 Inselspital, Bern University Hospital, Department of Medical Oncology, Bern, Switzerland. 8 Hospital de la Santa Creu i Sant Pau, Department of Medical Oncology, Barcelona, Spain. 9 Spanish Lung Cancer Group, (GECP), Barcelona, Spain. 10 Maastricht University Medical Center, Department of Pulmonary Diseases, Maastricht, Netherlands. 11 Hospital HM Sanchinarro, Centro Integral Oncología Clara Campal, Madrid, Spain. 12 Vall d’Hebron University Hospital, Department of Oncology, Barcelona, Spain. 13 Erasmus University Medical Center, Department of Pulmonary Medicine, Rotterdam, Netherlands. 14 University Hospital Geneva (HUG), Department of Oncology, Geneva, Switzerland. 15 Instituto Oncologico Veneto, Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy. 16 14 Hospital Universitario Puerta de Hierro, Department of Medical Oncology, Madrid, Spain. 17 ETOP IBCSG Partners Foundation, Coordinating Center, Bern, Switzerland. 18 European Institute of Oncology (IEO), IRCCS, Milan, Italy. 19 Centre Hospitalier Universitaire Vaudois (CHUV), Département d'Oncologie, Lausanne, Switzerland

Purpose/Objective:

Several randomised phase II trials have reported improved survival outcomes with the integration of definitive local therapy and systemic chemotherapy into a multimodality treatment regimen in patients with oligometastatic non small cell lung carcinoma (NSCLC). There is, however, limited data on integrating definitive local therapy into systemic chemotherapy and immunotherapy, which is a current standard of care for patients with metastatic disease.

Material/Methods:

CHESS is a prospective, international, multicentre, single-arm, phase II trial evaluating the efficacy and safety of the combination of chemotherapy, immuno-checkpoint inhibition and stereotactic body radiotherapy (SBRT), followed by definitive radiotherapy or surgery in patients with synchronous oligometastatic NSCLC (maximum 3 metastases, assessed by FDG-PET-CT and cranial MRI). Patients with an activating driver mutation, such as EGFR, ALK or ROS1, were excluded. Treatment consisted of an induction phase of durvalumab combined with 4-6 cycles of platinum-based doublet chemotherapy and upfront SBRT to all oligometastatic lesions. Patients who had not progressed at the 3-month restaging by FDG-PET-CT, underwent resection or definitive radiotherapy of the primary tumour, followed by continuation of durvalumab for up to 1 year. The primary endpoint was the 1-year progression-free survival (PFS) rate, with the aim of improving the 1-year PFS rate from 25% to 50%. A sample size of 42 evaluable patients provided 92% power to test this hypothesis, using an exact binomial test with a 1-sided alpha of 2.5% (success criterion: 17 patients without progression at 1-year).