Neutropenia in 6 ethnic groups from the Caribbean and the U.S.

ABSTRACT

BACKGROUND: Low white blood cell counts (WBC) or absolute neutrophil counts (ANC) may delay or prevent the completion of appropriate chemotherapy, especially among women receiving adjuvant therapy for breast and colon cancer, and affect cancer survival. Because race/ethnicity is also associated with survival, the authors compared WBC and ANC in healthy American-born women of African descent and European descent, and women from Barbados/Trinidad-Tobago, the Dominican Republic, Haiti, and Jamaica. METHODS: Blood samples from 261 healthy women ages 20 to 70 years were tested for WBC with differential, cytokine and growth factor levels, and ancestry informative and neutrophil elastase polymorphisms. The authors analyzed the association between neutropenia and serum WBC growth factor levels, cytokine levels, and neutrophil elastase c199a polymorphism. RESULTS: The median WBC and ANC differed among the 6 groups (P < .01 for WBC and P < .0001 for ANC). Dominicans were found to have higher median WBC and ANC than all other groups (P < .03). Neutropenia (ANC < 1500 cu/mm) was observed among 2.7% to 12.5% of the groups of predominantly African descent; no other groups were found to have neutropenia (P < .05). Granulocyte-colony-stimulating factor was found to be lower in white women, but tumor necrosis factor-alpha and C-reactive protein were not found to be correlated with ethnicity. Women of African origin were more likely to have polymorphisms of African ancestry (P < .001) and c199a alleles (P < .0001), which were also associated with low ANC levels. CONCLUSIONS: In the current study, the authors observed a strong association between neutropenia and African descent among asymptomatic women from the U.S. and the Caribbean. Among women of African descent who develop a malignancy, this association may contribute to racial disparities in treatment and outcomes.