Due to access barriers and socioeconomic obstacles, many American Indians and Alaska Natives (AIAN) with cancer are at risk for not completing recommended therapy. Despite these concerns, little is known about treatment and outcomes for AIAN with cancer. Important barriers to cancer outcomes research for AIAN stems from the relatively small proportion of AIAN cancer patients in any particular region, and limited scope of individual databases. In response, we propose to combine information from multiple states and databases to build a comprehensive resource for evaluating care and outcomes for AIAN diagnosed with lung, breast, colorectal, cervical, prostate, and ovarian cancer. To create this resource, we will link patient records from the Indian Health Service, state cancer registries, and Medicaid and Medicare enrollment and claims for AIAN cancer patients in California, Oregon, and Washington State. In addition, to identify potential barriers to care that are not easily recognized from administrative records, we will conduct interviews of AIAN cancer survivors and their caregivers in Oregon and Washington State. These interviews will focus on attitudes towards cancer and cancer care, provider-patient miscommunication, patient mistrust or misperceptions, cultural insensitivity, and racism and discrimination. Our study is greatly enhanced by the close working partnerships among the Fred Hutchinson Cancer Research Center, the Medicaid programs of all three states, and two tribal health boards with tribal epidemiology centers-one hosted at the Northwest Portland Area Indian Health Board, and the other a partnership among the California Rural Indian Health Board, the Riverside San Bernardino County Indian Health Inc., and the Indian Health Council Inc.