Race/ethnicity, socioeconomic status, and health system factors related to stage of presentation for newly diagnosed cancers in and insured population in southern California, 2015–2020.

e13810 Background: Stage of cancer at presentation may influence overall survival. Factors contributing to stage at presentation include access to care, participation in screening programs, and the effectiveness of systems of care. Race/ethnicity and lower socioeconomic status are sources of health disparities. Vertically integrated care systems may influence care delivery. Methods: We examined an insured Southern California cohort of 503,279 patients diagnosed with invasive cancer between Jan 1 2015 and Dec 31 2020. Data were provided by the state SEER Cancer Registry. We examined stage at diagnosis (SEER summary stage) as the dependent variable. Patients were defined as having local disease or advanced disease (regional or metastatic). We used geocoded socioeconomic status, race/ethnicity, and hospital of diagnosis as independent variables. For hospital of diagnosis, patients were divided into those diagnosed in Kaiser Foundation Hospitals or not. Other independent variables included age, sex, insurance type, and county. The prevalence of local disease was determined and logistic regression was used to determine the adjusted odd ratios of being diagnosed with local disease. Results: We found that Hispanic 0.92 (95% Confidence Intervals 0.9, 0.93), non Hispanic Black 0.87 (0.85, 0.9) and Asian/Pacific Islander 0.84 (0.83, 0.86) individuals were all less like to be diagnosed with local disease than non Hispanic Whites. Using the highest SES quintile as the reference we found other SES quintiles were less likely to be diagnosed with local disease with each quintile trending lower than the quintile above it. Upper Middle SES 0.92 (0.9, 0.93), Middle SES 0.86 (0.84, 0.88), Lower Middle SES 0.82 (0.81, 0.84), Lowest SES 0.79 (0.77, 0.81). Using non Kaiser Foundation Hospitals as the reference we found that patients diagnosed in Kaiser Foundation hospital were more likely to be diagnosed with local disease 1.14 (1.13, 1.16). Conclusions: Our analysis of a recent cohort of cancer patients in Southern California showed that Hispanic, non Hispanic Black and Asian/Pacific Islander individuals were all less likely to present with local disease than Whites . The likelihood of presenting with localized disease is greater for the highest SES with each lower quintile increasingly less likely than the quintile above. Lastly, we show that patients diagnosed in Kaiser Foundation hospitals are more likely to be diagnosed with local disease. Better understanding of these health disparities and the differences in hospital at diagnosis may help provide more equitable care.