Greening a chemotherapy day ward.

1567 Background: Cancer care is climate toxic and contributes to the triple planetary crisis which threatens human health and cancer care delivery. Despite this toxicity, sustainability guidelines in oncology are lacking. Our objectives are based on the sustainability touchpoints identified in previous research in our department. Study aims were to understand prescribing patterns, quantify plastic waste, and assess patients' and healthcare professionals' views on acceptability of proposed "green" strategies with the aim to develop a green prescribing checklist. Methods: A prospective review of systemic anti-cancer therapy (SACT) delivery at a tertiary oncology outpatient unit was performed. Variables collected included SACT regimen details, dosing interval extensions, supportive medication details and treatment value as rated by the ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS). Daily plastic waste output was measured. Anonymous surveys of patients and healthcare professionals were developed using previously validated questionnaires and circulated among adult patients attending cancer services locally and cancer care professionals nationally. Survey domains included sustainability knowledge, perceived barriers/facilitators, and willingness to adopt sustainability measures such as oral therapy. Findings were reported using descriptive statistics. Institutional and ethical approval was received prior to study commencement. Results: Selected findings show 23% (n=200/864) of supportive medications were given intravenously (IV). There was widespread adoption of subcutaneous formulations and extended dosing intervals. Most regimens with ESMO-MCBS scores showed substantial clinical benefit. Each patient attendance generated a mean of 46 grams of plastic waste. Seventy-two healthcare professionals responded to the survey; 97% (n=70/72) agreed that climate change adversely impacted human health and 82% (n=59/72) agreed that sustainable practices can decrease the effects of climate change yet only 15% (n=11/72) reported routinely considering environmental impacts when prescribing. Barriers to sustainable practices included time 65% (n=47/72), inadequate training 61% (n=44/72) and lack of institutional support 63% (n=45/72). A total of 211 patients submitted responses; 91% (n=190/208) agreed that reducing environmental impact should be a priority for hospitals, and 82% (n=159/194) were in favour of oral medications over IV where appropriate. Conclusions: This study, integrating provider and patient perspectives, demonstrates support for sustainable practices in oncology, but ad-hoc current implementation of same. The findings will guide development of a green checklist informed by patients and prescribers, followed by implementation and re-audit. Patient-centred strategies can align high value cancer care with planetary health and fill the current gap in sustainable oncology practice.