Racial differences in breast cancer risk to relatives of cases in the women's contraceptive and reproductive experiences (CARE) study

Abstract

9514 Background: Family history of breast cancer (BRCA) is a well-recognized risk factor for the disease, suggesting a role for genes, shared environment and/or cultural factors. Familial aggregation studies based primarily on Caucasian (CAU) women have given rise to age-specific and lifetime BRCA risk estimates, but less information is available on comparable risks for African American (AA) women. Methods: We used the family cancer history collected from CAU and AA participants with BRCA (cases) in the National Institute of Child Health and Human Development Women's CARE Study to compare the age-specific BRCA rates in their first-degree relatives (FDR). Kaplan-Meier cumulative hazard curves were obtained for FDR of CARE cases using PROC LIFETEST (SAS version 8.2). Analyses were pooled over all ages at diagnosis and stratified by age at diagnosis (< 45 vs. = 45) and race. Results: Age-specific risks (and standard errors) of BRCA to FDR of CARE cases, by race and age at BRCA diagnosis in the case, are presented in the table. By 40 years of age, BRCA risk to FDR is greater in AA than CAU, with the greatest risk, .023, in FDR of AA cases diagnosed by 45 years of age. By 70 years of age, BRCA risk to FDR is greater in CAU than AA, with the greatest risk, 0.16, in FDR of CAU cases diagnosed by 45 years of age. Conclusions: These results illustrate racial differences in age-specific BRCA risk and provide a recent update of these risks for both CAU and AA women that can be utilized in the clinical setting. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration National Institute of Child Health and Human Development; National Cancer Institute; Emory University; Fred Hutchinson Cancer Research Center; Karmanos Cancer Institute at Wayne State University; University of Pennsylvania; University of Southern California; Centers for Disease Control and Prevention; The Barbara Ann Karmanos Cancer Institute; United Foundation of Detroit; Michigan Health Care Education and Research Foundation