Clinical characteristics, response to therapy, and survival of African American patients diagnosed with chronic lymphocytic leukemia: joint experience of the MD Anderson Cancer Center and Duke University Medical Center.

ABSTRACT

BACKGROUND: Little is known regarding racial disparities in characteristics and outcomes among patients with chronic lymphocytic leukemia (CLL). METHODS: The characteristics and outcomes of untreated African American (AA) patients with CLL (n = 84) were analyzed and compared with a reference nonblack (NB) patient population (n = 1571). RESULTS: At the time of presentation, AA patients had lower median hemoglobin levels (12.9 g/dL vs 13.7 g/dL), higher ß2 microglobulin levels (2.7 mg/dL vs 2.4 mg/dL), greater frequency of constitutional symptoms (27% vs 10%), unmutated immunoglobulin heavy-chain variable region (IGHV) mutation status (65% vs 47%), ζ-chain-associated protein kinase 70 (ZAP70) expression (58% vs 32%), and deletion of chromosome 17p or chromosome 11q (28% vs 17%; P ≤ 02 for each comparison). Fifty-one percent of AA patients and 39% of NB patients required first-line therapy and 91% and 88%, respectively, received chemoimmunotherapy. Overall response rates to treatment were 85% for AA patients and 94% for NB patients (P = .06); and the complete response rates were 56% and 58%, respectively (P = .87). The median survival of AA patients was shorter compared with that of NB patients (event-free survival 36 months vs 61 months; P = .007; overall survival 152 months vs not reached; P = .0001). AA race was an independent predictor of shorter event-free and overall survival in multivariable regression models. CONCLUSIONS: The current results indicated that AA patients with CLL have more unfavorable prognostic characteristics and shorter survival compared with their NB counterparts.