Cancer health care disparities are complex, involve patient, clinician and health care system factors, and are defined as adverse differences in cancer outcomes. This analysis describes NCI's Healthcare Delivery Research Program's (HDRP) portfolio of disparities-focused research and identifies future research opportunities. Grants through HDRP (fiscal years 2012 to 2016) focused on detecting, understanding, and/or intervening on disparities in or among health disparity populations were reviewed by co-authors. Forty-eight funded grants were identified, coded, and characterized. Descriptive analyses are reported. Most studies focused on racial/ethnic minorities and socioeconomically disadvantaged groups. Colorectal, breast, and cervical cancers were most frequently examined. Almost 40% of studies addressed the intervening phase of the disparities research continuum. Few studies focused on clinician-level factors or involved the community in the research design. A sustained disparities research emphasis is essential to addressing the determinants of and cancer burden among health disparity populations across the cancer care continuum.
