Clinical characteristics, response to therapy, and survival of African American patients diagnosed with chronic lymphocytic leukemia

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 ¼ 84) were analyzed and compared with a reference nonblack (NB) patient population (n ¼ 1571). RESULTS: At the time of presentation, AA patients had lower median hemoglobin levels (12.9 g/dL vs 13.7 g/dL), higher b2 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%), f-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 firstline therapy and 91% and 88%, respectively, received chemoimmunotherapy. Overall response rates to treatment were 85% for AA patients and 94% for NB patients (P ¼.06); and the complete response rates were 56% and 58%, respectively (P ¼.87). The median survival of AA patients was shorter compared with that of NB patients (event-free survival: 36 months vs 61 months; P ¼.007; overall survival: 152 months vs not reached; P ¼.0001). 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. Cancer 2013;119:3177-85. V C 2013 American Cancer Society.

Analysis of racial variations in disease characteristics, treatment patterns, and outcomes of patients with chronic lymphocytic leukemia

“…Data that supported differential genetic risk for CLL exists between Black and White CLL patients led to the belief that biological differences might exist between W and NW CLL patients [15]. In fact, Falchi and colleagues analyzed outcomes of untreated African American patients as compared with non-black reference patients [16]. There was evidence of higher risk factors at the time of presentation such as higher beta-2-microglobulin, increased frequency of constitutional symptoms, more evidence of unmutated immunoglobulin heavy-chain gene, and deletions in 17p and 11q.…”

Fine-mapping of HLA associations with chronic lymphocytic leukemia in US populations

“…51,52 In a recent review of the clinical course of African Americans with CLL, investigators from the MD Anderson Cancer Center and Duke University Medical Center reported that African Americans tend to have more unfavorable clinical and biologic characteristics, an earlier need of treatment, fewer remissions, and inferior overall survival compared with nonblack patients. 53 Despite a lower overall incidence of CLL in African Americans, the somewhat more aggressive clinical course suggests that these differences may not be accountable strictly by differences in socioeconomic status. We report for the first time that the HLA alleles predisposing to the development of CLL in African Americans are different than those for whites, and this may have implications for mechanism of evasion of immune surveillance that normally functions to suppress burgeoning malignancies.…”

Disparities in lymphoma on the basis of race, gender, HIV status, and sexual orientation

“…Similar observations have been noted in chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Black patients with CLL/SLL often present with worse prognostic indicators such as increased beta-2 microglobulin levels, worsening anemia, higher Rai stage, and unfavorable cytogenetic markers compared to white patients (5,6). Additionally, Coombs et al noted that black patients with CLL/SLL have a decreased event free survival and overall survival (OS) compared to white patients (5).…”