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

Cancer. 2013 Sep 1;119(17):3177-85. doi: 10.1002/cncr.28030. Epub 2013 Jul 8.

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 β2 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.

Keywords: African Americans; Chemoimmunotherapy; Chronic Lymphocytic Leukemia; Prognostic Factors; Racial Disparities; Survival.

Publication types

  • Comparative Study

MeSH terms

  • ADP-ribosyl Cyclase 1 / analysis
  • Academic Medical Centers
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor* / blood
  • Biomarkers, Tumor* / genetics
  • Black or African American / genetics*
  • Black or African American / statistics & numerical data*
  • Chromosomes, Human, Pair 17
  • Disease-Free Survival
  • Female
  • Gene Deletion
  • Gene Expression Regulation, Neoplastic
  • Health Status Disparities*
  • Humans
  • Immunoglobulin Heavy Chains / genetics
  • Immunoglobulin Variable Region / genetics
  • Kaplan-Meier Estimate
  • Leukemia, Lymphocytic, Chronic, B-Cell / diagnosis
  • Leukemia, Lymphocytic, Chronic, B-Cell / drug therapy
  • Leukemia, Lymphocytic, Chronic, B-Cell / epidemiology
  • Leukemia, Lymphocytic, Chronic, B-Cell / genetics*
  • Leukemia, Lymphocytic, Chronic, B-Cell / immunology
  • Leukemia, Lymphocytic, Chronic, B-Cell / mortality*
  • Leukemia, Lymphocytic, Chronic, B-Cell / therapy
  • Male
  • Medical Records Systems, Computerized
  • Middle Aged
  • North Carolina / epidemiology
  • Risk Assessment
  • Risk Factors
  • Texas / epidemiology
  • ZAP-70 Protein-Tyrosine Kinase / genetics
  • beta 2-Microglobulin / blood

Substances

  • Biomarkers, Tumor
  • Immunoglobulin Heavy Chains
  • Immunoglobulin Variable Region
  • beta 2-Microglobulin
  • ZAP-70 Protein-Tyrosine Kinase
  • ZAP70 protein, human
  • ADP-ribosyl Cyclase 1