Rapid advances in cancer research, the development of new and more sophisticated approaches to diagnostic testing, and the growth in targeted cancer therapies are transforming the landscape of cancer diagnosis and care. These innovations have contributed to improved outcomes for patients with cancer, but they have also increased the complexity involved in diagnosis and subsequent care decisions. To examine opportunities to improve cancer diagnosis and care, the National Academies of Sciences, Engineering, and Medicine developed a two-workshop series. The first workshop, held on February 12–13, 2018, in Washington, DC, focused on potential strategies to ensure that patients have access to appropriate expertise and technologies in oncologic pathology and imaging to inform their cancer diagnosis and treatment planning, as well as assessment of treatment response and surveillance. This publication chronicles the presentations and discussions at the workshop.