Breast Stem Cells in Women at Average Risk and Increased Risk for Breast Cancer

Background: * Research suggests that breast cancers may arise from a population of stem cells in the normal mammary gland that produce clones of cancer cells. * Researchers are now trying to determine what events may initiate the formation of cancer cells. Objectives: * To look for and describe breast stem cells from normal breast tissue from women who do not have breast cancer. * To compare the breast stem cells between women at increased risk for breast cancer and women at average risk for breast cancer. * To show a relationship between the number and type of breast stem cells with the density (appearance) of the mammogram (breast x-ray). * To make cell cultures (grow cells under controlled conditions) from the breast stem cells. Eligibility: -Women 18 years of age and older who are at average or increased risk for breast cancer. Design: Participants complete a health history questionnaire, family history questionnaire and risk assessment questionnaire. * Participants have a mammogram and breast biopsy (surgical removal of a sample of breast tissue). * Women who can become pregnant have a urine pregnancy test....

Background: Emerging models of breast cancer suggest that breast cancers arise from a population of stem cells that are present in the normal mammary gland. The stem cell produces a clone of cancer cells. Researchers are now attempting to isolate and characterize breast stem cells and determine what events may initiate the tumorigenic process. Objectives: To identify and characterize breast stem cells from normal breast tissue from women who are free of breast cancer. To compare characteristics of breast stem cells between women at increased risk for breast cancer and women at average risk for breast cancer. To correlate breast stem cell number or characteristics with mammographic density. To establish cell cultures of breast stem cells from women at increased risk for breast cancer and women at average risk for breast cancer. Eligibility: Women who are at average or increased risk for breast cancer and over age 18 will be eligible. Design: This is a pilot tissue acquisition trial. Breast biopsies will be obtained from all subjects and breast cancer risk demographics will be collected at one time point. We aim to enroll 20 average risk and 20 increased risk women.