Abstract 2628: Racial differences in the impact of socioeconomic status on cancer-specific survival in multiple myeloma

Background: Multiple myeloma (MM) incidence and outcomes differ across racial/ethnic groups in the United States. Interactions between socioeconomic status (SES) with ethnicity in MM incidence and survival outcomes are not well understood. Our objective was to evaluate disparities in cancer-specific survival of patients diagnosed with MM by race/ethnicity. Methods: We conducted a population-based retrospective cohort study of patients ages 20+ years diagnosed with MM between 2000 and 2015 using Surveillance, Epidemiology and End Results, Census Tract-level SES and Rurality Database. SES was defined using the National Cancer Institute's time-dependent composite score developed by Yost et al. (2001). Yost index quintiles were where the 1st and 5th quintiles representing the lowest and highest SES categories respectively. Cumulative incidence functions were used to analyze cancer-specific survival across strata racial/ethnic and SES and equality of functions was determined using Gray's test. Subdistribution hazard ratios (SHR) and 95% confidence intervals (CI) were calculated using the Fine and Gray regression models adjusted for age, sex, year of diagnosis, marital status, insurance status, and treatment with chemotherapy. Race-specific risk estimates were stratified by age (