Abstract Kaiser Permanente (KP) is an ideal environment to study the spectrum of cancer prevention and control because it provides comprehensive cancer care to a large and diverse community. The Kaiser Permanente Research Bank (KPRB) is collecting biospecimens and a survey of health-related behaviors and other risk factors from about 400,000 adults aged 18 years and older across all eight KP regions. The KPRB includes a cancer cohort and cases are identified from KP region-specific algorithms designed to identify cancer cases within days of diagnosis, and from linkage with regional tumor registries. KPRB participation involves completing an online informed consent and survey, and providing a blood or saliva sample. KPRB participants consent to linkage to their electronic health record (EHR), which includes comprehensive information about cancer screening, diagnosis and treatment. A key strength of this cohort is its diversity with respect to age, race/ethnicity, and geographic location (Hawai’i, Oregon, Washington state, California, Colorado, Georgia, and the Washington, DC area). To date, the KPRB includes 68,000 cancer cases, 56% are women, and 30% are non-white. Over 8,500 cases were diagnosed before the age of 50 and the cohort includes substantial numbers of cancer cases among Asian and Pacific Islanders (n=8,941), Hispanics (n=7,678), and non-Hispanic blacks (n=5,367). Although all cohort members have insurance, and thus, presumably access to care, we observed disparities in stage at diagnosis. Compared to non- Hispanic whites, non-Hispanic Blacks are more likely to be diagnosed at stage 4 (5% versus 16%, respectively, of all cases); participants describing themselves as multi- racial or “other” race similarly have a very high proportion (25%) of cases diagnosed at stage 4. Research is planned to examine the factors associated with this disparity. The extensive EHR, access to stored tissue specimens, detailed treatment data, and ability to follow patients over time for recurrence and mortality make the KPRB Cancer Cohort an exceptional resource for exploring the factors that contribute to cancer etiology, progression, and survival. We invite investigators to apply to use the KPRB (https://researchbank.kaiserpermanente.org/) to accelerate progress toward improving cancer care. Citation Format: Heather S. Feigelson, Christina Clarke, Andrea Burnett- Hartman, Stephen Van Den Eeden, Sheila Weinmann, Monica Ter-Minassian, Stacey Honda, Deborah Young, Aruna Kamineni, Sarah Rowell, Alan Bauck, Elizabeth McGlynn. The Kaiser Permanente Research Bank cancer cohort: A diverse resource to improve cancer care [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-178.