Introduction: California is home to the largest ethnic/racial diversity in the US, with 39% Latino, 37% White, 15% Asian American, 6% African American, 3% multiracial, <1% American Indian, and <1% Pacific Islander. The top five site specific cancer incidence rates are prostate, breast, lung and bronchus, colon and rectum, and corpus uteri, while the top five mortality rates are lung and bronchus, prostate, colon and rectum, breast and pancreas. However, incidence and mortality rates vary considerably between Asian Pacific Islanders, Blacks, Hispanics, and Whites. The purpose of this observational study was to explore factors that could contribute to higher cancer mortality, including later stage diagnoses and receipt of National Comprehensive Cancer Network (NCCN) adherent care by site in California. Methods: This is a retrospective population-based cohort study of patients with seven types of invasive cancer using the California Cancer Registry from 2004-2016. Patient characteristics included race/ethnicity (including Chinese, Japanese, Filipino, Korean, Vietnamese and Asian Indian subgroups), insurance, socioeconomic status, tumor stage and grade. Adherence with NCCN guidelines was defined by appropriate surgical, radiation, and chemo- or hormonal therapies. Multivariate logistic regression model was fit to evaluate the relationship between patient and tumor characteristics and guideline adherence. Disease-specific survival analyses used multivariate proportional hazards model. All multivariate analyses controlled for age, year, insurance type, SES, marital status, sex, and tumor stage and grade. Results: Overall, less than half of all cancer patients received NCCN adherent care, and patients receiving non-adherent care had worse disease-specific survival. Compared to Whites, Blacks had the highest proportions of later stage diagnoses for breast, cervical and ovarian cancers; they were also less likely to receive guideline adherence care for breast, colon, and ovarian cancers. Hispanics had the highest proportion of later stage diagnoses for gastric cancer; they were also less likely to receive guideline adherent care for breast and liver cancers. Filipinos had the highest proportion of later stage diagnosis for liver cancer; Koreans had the highest proportions for colon and rectum cancers, and were less likely to receive guideline adherent care for colon cancer. Blacks had significantly lower survival for breast, colon, stomach, ovarian and cervical cancers; Hispanics, Filipinos and Vietnamese had significantly lower survival for gastric cancer. Conclusions: Significant improvements are needed in cancer early detection, quality care and survival among California’s ethnic/racial populations. Unfortunately, the current COVID-19 pandemic has exacerbated racial and ethnic disparities in screening and early detection, and compounded the difficulties in access to quality cancer care.

Citation Format: Sora P. Tanjasiri, Kiran Clair, Jenny Chang, Argyrios Ziogas, Greg Gin, Kari J. Kansal, Jason Zell, Robert Bristow. Ethnic/racial differences in later stage diagnoses, NCCN adherent care and survival in California [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-149.