Over a decade ago, the Institute of Medicine called for a national cancer data system in the United States to support quality-of-care assessment and improvement, including research on effective interventions. Although considerable progress has been achieved in cancer quality measurement and effectiveness research, the nation still lacks a population-based data infrastructure for accurately identifying cancer patients and tracking services and outcomes over time. For compelling reasons, the most effective pathway forward may be the development of state-level cancer data systems, in which central registry data are linked to multiple public and private secondary sources. These would include administrative/claims files from Medicare, Medicaid, and private insurers. Moreover, such a state-level system would promote rapid learning by encouraging adoption of near-real-time reporting and feedback systems, such as the Commission on Cancer's new Rapid Quality Reporting System. The groundwork for such a system is being laid in the state of Georgia, and similar work is advancing in other states. The pace of progress depends on the successful resolution of issues related to the application of information technology, financing, and governance.