Epidemiological and clinical data as breast cancer predictors in African American and Caucasian women

A56

Reproductive and family histories are independently associated with breast cancer. This is in part due to the fact they are indirect measures of individual exposure to endogenous estrogens. It is known that women of different ethnicities exhibit differences in estrogen levels and metabolism, thus exhibiting a variety of risk profiles. A clinical marker of breast cancer risk is mammographic density; however, it is not known if any difference exists with ethnicity. This study attempts to identify breast cancer risk profiles among Caucasian and African American women. The sample population was drawn from the Mammograms and Masses Study, conducted on approximately 1,000 women in the Greater Pittsburgh area. All African-American controls with mammogram data were selected, and Caucasian controls were randomly selected for this analysis with frequency matching 2:1. Selected variables that are known to be associated with breast cancer were evaluated according to ethnicity. Statistical significance was assessed using the 2-sample t-test or chi-square statistic, where appropriate.
 Mean Age: Afr-Amer, 55.5 yrs; Cau, 55.5 yrs; P=0.9898
 Age at Menarche > 13 yrs: Afr-Amer, 55.9 yrs; Cau, 63.6 yrs; P=0.4395
 Age at Menopause: Afr-Amer, 44.8 yrs; Cau, 46.9 yrs; P=0.1281
 Ever Pregnant: Afr-Amer, 82.9%; Cau, 76.6%; P=0.4561
 Ever Smoker: Afr-Amer, 57.1%; Cau, 40.3%; P=0.0963
 Family History of Cancer: Afr-Amer, 45.5%; Cau, 71.4%; P=0.0095
 Body Mass Index (BMI): Afr-Amer, 31.6; Cau, 27.4; P=0.0002
 Breast Density: Afr-Amer, 28.3%; Cau, 40.1%; P=0.0050
 Preliminary results on the mean 2:16 α hydroxyestrone metabolite ratio among a subset of the study population suggest differences in estrogen metabolism (0.48 African Americans, 0.66 Caucasians, p-value= 0.1272). Laboratory testing of the remaining population is ongoing. In this study population, breast density, BMI, family history of cancer and estrogen metabolism vary by race. Our findings support the need for breast cancer studies within a large African American population, where genetic and environmental factors should be explored.