274 Background: The objectives of the formative research were to identify key themes of patient-centered cancer care and determine the best method to collect data to develop the CAHPS Survey for Cancer Care Prototype. This survey seeks to measure aspects of care most important to patients and allow comparisons of those aspects across treatment centers and treatment modalities. Methods: We developed a library of 1,781 items from CAHPS and cancer care surveys. We conducted 14 focus groups with patients (including 2 conducted in Spanish) who had received cancer care in the past 12 months, and 2 focus groups involving family members of cancer patients. We met with 10 experts representing patients and survivors, or who had expertise in quality improvement, oncology, shared decision-making and patient safety to obtain feedback on the development of the survey, potential markets for the instrument, and to assist with overall strategy. Finally, we conducted separate interviews with 5 stakeholder groups representing oncology associations to obtain feedback on focal provider, attribution and sampling. Results: While the focus group results validated findings from the item library, new concepts also emerged, such as the need for having a plan of care. Patients most readily identified with a team of providers, rather than a single provider. The two most important domains to patients were (1) how well the cancer care team communicates with patients and (2) whether the cancer care team keeps patients informed about cancer treatment. Patients were also interested in care coordination, access to information, providers who are up-to-date, and shared decision-making. Stakeholder interviews noted that survey results would be most valuable if presented by treatment modality: medical, radiation, and surgical oncology. Conclusions: These findings suggest that cancer care is best for the patient when providers are knowledgeable and straightforward with medical information, yet can demonstrate empathy and compassion.