Epidemiology of Breast Cancer Subtypes in African-American Women

The purpose of this collaborative Program Project is to understand the etiology of specific subtypes of breast cancer in African American women, in particular, the basal-like subtype, which occurs about twice as often in African American women as in other ethnic groups and is associated with a worse prognosis than other subtypes.   Questionnaire, genetic, and pathology data from four large epidemiologic studies, including the Black Women’s Health Study (BWHS), will be pooled in order to have sufficient numbers of cases of the basal-like subtype.  The data coordinating center will reside at the Slone Epidemiology Center.  Archived tumor blocks will be requested from the pathology departments of hospitals where study participants receive treatments.  Tumor tissue microarrays will be created and the tissue will be assayed by immunohistochemistry to establish the subtypes.  Both non-genetic and genetic factors will be assessed in relation to breast cancer subtypes.  In addition, analyses of gene-environment interactions will be carried out.