Impacts of climate change on cancer risk, clinical outcomes, and care delivery: A scoping review

Background: While some interactions between climate change and health have been well documented, the complex relationship between climate change, its proximate causes, and cancer is less clear. This scoping review was conducted to survey specific elements within existing peer-reviewed and grey literature addressing the impacts of climate change-related exposures on 1) cancer risks, 2) outcomes, and 3) care delivery. Methods: Following PRISMA guidelines, peer-reviewed and selected grey literature on these topics were identified using pre-specified eligibility criteria. Structured searches by independent reviewers and data extraction from multiple electronic databases were performed, from which syntheses were generated and research gaps identified. Results: Of 542 studies identified by title/abstract for full-text review, 182 studies were eligible for data extraction. Of these, 127 examined fossil fuel-related pollutant levels and excess cancer risks, 29 investigated the impact of climate change on cancer outcomes, and 31 examined the impact of climate change-related events on cancer care delivery. Overall, the effects of climate change-related exposures, or climate change's proximate causes, lead to increases in cancer risk. Climate change effects such as extreme weather events disrupt care and impact survival outcomes. Across these subject areas, climate change-related events’ exacerbation of existing healthcare disparities was an emergent theme. Conclusions: Climate change has impacts across the cancer care continuum. Research gaps include limited data on the direct effect of climate change on cancer outcomes and care delivery, population health research, and mitigation efficacy. More work is needed in education, adaptation, and climate preparedness for cancer patients and healthcare systems.