Influence of racial and ethnic identity on overall survival in patients with chronic lymphocytic lymphoma.

Abstract

7508 Background: Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia and results in highly variable clinical outcomes. Epidemiologically, CLL occurs in White ethnicity more frequently and thus, CLL outcomes among underrepresented minorities are not well studied. We sought to examine differences in treatment patterns and survival outcomes based on racial identity of CLL patients and how these have changed over time. Methods: The National Cancer Database was used to identify CLL patients diagnosed from 2004-2018. Demographic and treatment characteristics were compared between White, Black, Asian, Hispanic and other minority groups. Kaplan Meier and adjusted Cox regression survival analysis were used to compare overall survival (OS) between races. Survival analysis was repeated by year of diagnosis in Black and White populations. Results: Of 97,804 CLL pts identified, 90.7% of patients were White, 7.6% Black (N = 7,391), 2.6% Hispanic (N = 2,487), 0.6% Asian (N = 613), and 1.1% were other. Compared to White pts, Black pts were younger at diagnosis (median age 66 years [interquartile range 61-79] vs. 70 years [range 58-75], more likely to have ≥1 comorbidity (27.9% vs. 21.3%), and be uninsured (6.6% vs. 2.1%) (all p < 0.001). Black pts were more likely than White pts to have CLL directed treatment immediately after diagnosis (35.9% vs 23.6%; p < 0.001). With a median follow-up of 4.3 years, median OS for all CLL patients was 9.0 years (CI 8.9-9.1 years). Black pts had a shorter median OS of 7.0 years (CI 6.7-7.3 years) compared to White pts (9.14 years [CI 9.0-9.3]), p < 0.001), as well as inferior OS at 5-years (61% vs. 69%) and 10-years (36% vs. 46%), p < 0.001. On multivariate analysis adjusted for age and Charlson-Deyo score, Black race was independently associated with shorter OS (HR 1.51 [CI 1.46-1.57], p < 0.001). While OS lengthened with successive year of diagnosis for all races, the relative survival of Black compared to White pts did not improve over the observed time period. Referenced to the White population, Black pts diagnosed between 2004-2006 had a HR of 1.64 (CI 1.52-1.76) for mortality, and those diagnosed between 2016-2018 had a HR of 1.64 (CI 1.44-1.85). Conclusions: We present the largest study to date describing racial disparities in CLL. Black pts have significantly shorter OS compared to White pts, which is sustained when adjusted for the higher prevalence of comorbidities in the Black CLL population. Unfortunately, the survival gap between White and Black patients has not improved since 2004, highlighting the need for targeted research directed at improving survival in Black pts with CLL. [Table: see text]