Improving cancer care while reducing its carbon footprint: GHG-mitigating strategies highlighted at ESMO 2025

BACKGROUND: The environmental impact of cancer care is an emerging concern, yet therapeutic strategies that may incidentally reduce greenhouse gas (GHG) emissions remain poorly described. The 2025 ESMO Congress, where nearly 3000 abstracts were presented, offered an opportunity to identify clinically validated approaches that could lower the carbon footprint of oncology. METHODS: All abstracts from the 2025 ESMO Congress were reviewed. Studies suggesting meaningful downstream reductions in drug use, visit frequency, treatment duration, or overall care intensity were selected. For each, GHG emissions were estimated using the ECOVAMED drug carbon-footprint database and standard emission factors. RESULTS: Ten abstracts were identified. They spanned primary prevention, therapeutic de-escalation, reduced dose or duration of systemic therapy, biomarker-guided treatment selection, and non-pharmacological interventions. Several strategies demonstrated non-inferior or improved clinical outcomes while substantially lowering treatment-related emissions. Notably, none of the selected studies had explicitly assessed environmental impact. CONCLUSIONS: Multiple strategies presented at ESMO 2025 appear capable of improving patient outcomes while reducing the environmental burden of cancer care. Systematically integrating environmental endpoints into clinical research would help identify such win-win approaches and advance a more sustainable oncology practice.