In oncology, clinical trials are of utmost importance to advance treatment options and management of cancer care. However, there is growing awareness concerning the environmental impact of health care practices. This has led to urgent demands for action.^{1 - 5} Research conducted in the United Kingdom has revealed that the carbon footprint of clinical trials is substantial, with the main contributors including travel required for these trials, the delivery of trial drugs, and the inefficiencies in enrolling participants.⁶ Of the 350,000 clinical trials registered acro ss the globe, it is estimated that this equates to a carbon consumption of 27.5 million tons.⁷ As part of the National Health Service, the Sustainable Healthcare Coalition has set up resources and a working tool to test on clinical trials to measure carbon emissions, and the National Institute for Health and Care Research has published a Carbon Reduction Guide. However, in the United States, such measures have not been implemented. Thus, we present the following suggestions for the reduction of environmental toxicity within US cancer clinical trials.

1. Explore opportunities for decentralized clinical trials : Recognizing that patients frequently face the challenge of traveling long distances to participate in trials,⁸ we encourage the leveraging of community partnerships aimed at exploring the feasibility of decentralizing clinical trials. Recent studies have indicated that travel and driving distance for individual radiation therapy treatments are significant contributors to emissions related to cancer care.^{9 - 11} By exploring this approach, we could potentially reduce travel-related emissions while also expanding access, thereby mitigating financial burdens and socioeconomic disparities in trial enrollment.¹²

2. Enhanced transportation and housing assistance : To address the issue of long travel distances, we advocate for increased access to public transportation, charity care, and affordable housing for patients requiring multiday treatments. This strategy may significantly lessen both the environmental impact and financial strain associated with travel for clinical trials.

3. Streamlined appointment scheduling : We suggest partnering with cancer care navigators to effectively streamline and consolidate appointments for patients during clinical trial enrollment. Such strategic coordination has the potential to minimize the need for frequent long-distance travel, thereby leading to a more efficient trial participation process and contributing to a reduction in emissions.

4. Enhanced utilization of telehealth : Given the increasing adoption of and documented advantages of telehealth, such as the 36% reduction in greenhouse gas emissions observed at Stanford Health Care since 2019,¹³ integrating telemedicine into the clinical trial framework is advisable. Studies indicate that telehealth in oncology not only lowers carbon emissions associated with cancer care but also mitigates financial toxicities for patients and increases access to those in rural settings.^{14 - 16} Its application is especially beneficial in assessing patient eligibility and reducing unnecessary travel.

5. Prospective environmental data collection : We advocate for the proactive collection of environmental impact data from the onset of the start of clinical trials. This initiative should be conducted in collaboration with environmental science schools or departments and involve climate health experts. Precise tracking of emissions throughout each phase of a trial is crucial for making well-informed decisions.

6. Integration of environmental considerations in regulatory frameworks : We encourage consideration of modifying the clinical trial authorization and regulatory submission processes to include an assessment of the environmental impact of the trials. This environmental evaluation should be considered as critical as the evaluation of cost, equity, and access in the regulatory process.

7. Interdisciplinary collaboration : We call for a concerted effort among oncology teams, environmental specialists, and cooperative groups to devise holistic strategies. These strategies should aim to lower the costs for patients and health care institutions, broaden the accessibility of clinical trials, and reduce the overall carbon footprint associated with these trials.

By implementing these recommendations, we can address the environmental impact of clinical trials while improving accessibility and reducing financial burdens on patients.