City Cancer Challenge (C/Can) supports cities around the world as they work to improve access to equitable, quality cancer care. It leads a city-based partnership initiative that aims to improve access to quality cancer care in cities around the world by transforming the way stakeholders from the public and private sectors collectively design, plan, and implement cancer solutions. The approach is built on the core principle that cities can drive impact at national level by crafting data-driven solutions with the support of a network of global, regional, and local partners that reflect an understanding of the unique local context. C/Can was launched by the Union for International Cancer Control (UICC) at the 2017 World Economic Forum Annual Meeting in Davos. It was established as a standalone Swiss foundation in January 2019.