Racial Differences in the Overall Survival of Hairy Cell Leukemia in the United States: A Population-Based Analysis of the Surveillance, Epidemiology, and End Results Database

BackgroundSeveral studies have reported excellent long-term overall survival (OS) of patients with hairy cell leukemia (HCL) without racial disparity. Studies in other cancers have demonstrated worse mortality among African American (AA) individuals.Patients and MethodsWe used the Surveillance, Epidemiology, and End Results 18 database to identify HCL patients diagnosed between 1978 and 2011. Kaplan–Meier curves were plotted to estimate OS. Univariate analysis using the life table method and multivariate Cox regression model were used to determine the independent effect of race on OS.ResultsThe study population included 78% men and had a median age of 56 years. Race included 93% white, 3.5% Asian/Pacific Islander, and 3.5% AA. The 10-year OS was significantly less for AA as compared with white and Asian/Pacific Islander individuals (54% vs. 72% vs. 75%; P < .001). A Kaplan–Meier survival curve showed a significantly worse OS for AA versus other races (P < .001). In a multivariate analysis, AA race remained an independent predictor for a worse OS (hazard ratio 1.77; 95% confidence interval, 1.30-2.40; P < .001) after adjusting for age, sex, year of diagnosis, and marital status.ConclusionIn this population-based study, only half of AA patients but more than two-thirds of HCL patients from other racial groups were alive at 10 years. Such drastic racial differences in OS of HCL patients at the population level mandates further evaluation of the contributory biological, socioeconomic, health system, and other factors. Understanding and overcoming such racial disparities might close the racial differences in OS of this potentially curable disease.