Alternative bevacizumab schedule in high-grade gliomas recurrence is associated with reductions in greenhouse gas emissions without loss of clinical efficacy

Background Health care contributes significantly to global carbon emissions. In oncology, reducing the environmental impact of treatment is essential. Bevacizumab, with or without lomustine, is a widely used option in recurrent high-grade gliomas. While the usual dosing is 10 mg/kg every 2 weeks, a 15 mg/kg every-3-weeks regimen has shown similar efficacy and safety. This study aimed to compare these two schedules in terms of survival, tolerance, and carbon emissions in a real-world setting. Methods We conducted a retrospective, single-center, observational study at Bordeaux University Hospital. Patients treated between January 2022 and August 2024 with bevacizumab plus lomustine for IDH-wildtype high-grade gliomas recurrence were included. Two cohorts were compared: one receiving bevacizumab every 2 weeks and the other every 3 weeks. Data on overall survival, progression-free survival, toxicities, and care-related carbon emissions were collected. Results 62 patients were included: 44 in the every-2-week group and 18 in the every-3-week group. Median overall survival was 6 months [95% CI: 5–8] and 7 months [95% CI: 4–9], respectively (log-rank p = 0.69). Progression-free survival and tolerance were broadly similar between groups. The estimated carbon footprint of one visit to day hospital for a bevacizumab infusion was 63 kg CO₂e. Nationally, in France, shifting to a 3-week schedule could reduce emissions by approximately 330 tonnes of CO₂e per year, based on incidence data. Conclusion This retrospective analysis showed broadly similar outcomes between regimens, with potential environmental benefits. These exploratory findings require prospective validation.