Interfaces across the cancer continuum offer opportunities to improve the process of care.

while reducing their adverse consequences. In this supplement, we explore the processes involved with comprehensive cancer care and emphasize the interfaces between providers, providers and patients, and health-care organizations. Consistent with Donabedian’s conception of the health-care process, these interfaces are affected by the structure of the environment in which they arise as well as by the practices, organizations, and communities where the processes occur. This concluding article summarizes how the supplement identifies the challenges at the interfaces of cancer medical care practice and proposes how further research regarding these interfaces could have implications for the goal of achieving a system of cancer care that is safe, effective, patient centered, timely, efficient, and equitable (4).