S370
Clinical - CNS
ESTRO 2026
1 Sussex Cancer Centre, University Hospitals Sussex NHS Foundation Trust, Brighton, United Kingdom. 2 Department of Biochemistry and Biomedicine, University of Sussex, Brighton, United Kingdom. 3 Edinburgh Cancer Centre, NHS Lothian, Edinburgh, United Kingdom. 4 School of Regeneration and Repair, University of Edinburgh, Edinburgh, United Kingdom. 5 Beatson West of Scotland Cancer Centre, NHS Greater Glasgow and Clyde, Glasgow, United Kingdom. 6 Department of Clinical Neurosciences, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom. 7 Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom. 8 Department of Neurosurgery, University Hospitals Sussex NHS Foundation Trust, Brighton, United Kingdom. 9 Section of Neurosurgery, University of Otago, Dunedin, New Zealand Purpose/Objective: Glioblastoma has limited therapeutic options. Despite extensive surgical resection, glioblastoma will recur, frequently around the resection cavity. Dose-escalated radiotherapy failed to improve outcomes, whilst re- resection and re-irradiation at recurrence remain of uncertain benefit. The development of novel local approaches, including locally delivered viral immunotherapy, shows promise. However, early identification of efficacy of novel approaches requires an awareness of modern outcomes for glioblastoma patients. We sought to describe real-world outcomes following optimal 1st line treatment and explore survival following re-resection at recurrence. Material/Methods: Using two independent real-world datasets of glioblastoma patients (Histo-Mol GBM collaborative and Edinburgh cohorts), we analysed survival outcomes for patients following surgery at diagnosis and recurrence. Overall survival (OS) was calculated using the Kaplan-Meier method from date of surgery to death from any cause, whilst progression free survival (PFS) was calculated from date of surgery to imaging or clinician defined progression or death. Results: A total of 513 (Histo-Mol n=451, Edinburgh n=62) glioblastoma patients who underwent optimal 1st line treatment (extensive surgical resection [>95% for Histo-Mol or >90% Edinburgh] plus concurrent chemoradiotherapy) were identified. Patients in the Histo-Mol cohort had surgery in 2021 and patients in the Edinburgh cohort had surgery between 2014 and 2019. For all 1st line patients treated with conventionally fractionated chemoradiotherapy (“Stupp”1), median PFS was 10.4/9.2 months, median OS was 18.7/18.4 months, and 18-month OS rates were 53.7%/52.3% for Histo-Mol and Edinburgh patients respectively, with similar findings for patients aged <70 receiving maximal therapy (>95/90%
resection followed by “Stupp”1). For patients 70+ treated maximally (>95% resection followed by hypofractionated chemoradiotherapy (“Perry”2)) median PFS was 9.8 months, median OS was 17.0 months, and 18-month OS was 47.1% in the Histo-Mol cohort. Additionally, 120 patients (Histo-Mol cohort only) who underwent re-resection at first recurrence were identified. Median PFS was 3.9 months and OS was 7.5 months, whilst 6- and 12-month OS rates were 65.1% and 32.0% respectively. For patients <70, median PFS was 3.8 months, median OS was 7.6 months, and 6-month and 12-month OS rates were 66.6% and 32.6% respectively.
Conclusion: We provide real-world benchmark survival data for glioblastoma patients undergoing optimal first line treatment and re-resection at recurrence. The highly concordant OS but slightly different PFS figures between cohorts may reflect variability in calling progressive disease, suggesting PFS is a less robust endpoint than OS. These data will be useful to power future studies of novel local therapies for patients with
glioblastoma. References:
1. Stupp R, Mason WP, van den Bent MJ, et al. Radiotherapy plus Concomitant and Adjuvant Temozolomide for Glioblastoma. N Engl H Med. 2005;352(10):987-96.2. Perry J, Laperriere N, O'Callaghan CJ, et al. Short-Course Radiation plus Temozolomide in Elderly Patients with Glioblastoma. N Engl J Med. 2017;376(11):1027-37. Keywords: Glioblastoma, maximal treatment, survival
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