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

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.

- INCLUSION CRITERIA:

Women age 18 and older.

No abnormal findings in the breast by physical examination.

Average Risk: must meet all criteria below.

- Gail model index of less than 1.7% over next 5 years.

- Claus model lifetime risk less than 10%.

- BRCAPro and Couch model less than 10% of being a BRCA mutation carrier OR tested
negative for documented deleterious BRCA1/2 mutation in family.

Increased risk for invasive breast cancer by one of the following:

- Gail Model risk of greater than 1.7% over 5 years from study entry.

- Claus model lifetime risk to age 79 greater than or equal to 10%.

- History of high risk pathologic lesion: lobular carcinoma in situ, atypical
hyperplasia, DCIS (ductal carcinoma in situ).

- Deleterious mutations in BRCA1/2, PTEN or P53.

- Greater than or equal to 10% chance of carrying BRCA1/2 gene mutation as assessed by
BRCAPro and Couch model (22, 23). If a woman has a 20% risk of carrying a BRCA1/2
mutation by either model, she will meet eligibility criteria.

- History of unilateral breast cancer either invasive or in situ, and a normal
contralateral breast by physical examination.

Willing to stop NSAIDS for 3 days prior to biopsy and aspirin 7 days prior to biopsy.

If history of cancer (other than squamous or basal cell skin cancers), subject must have
no evidence of disease at time of enrollment AND no history of cancer directed treatment
in the 3 months preceding enrollment.

Identification of dense area of breast tissue suitable for biopsy identified on mammogram
by the radiologist.

EXCLUSION CRITERIA:

Current use of hormonal therapies (e.g. tamoxifen, aromatase inhibitors, hormone
replacement therapy, oral contraceptive pills, topical or vaginal hormone medications are
allowed.)

Chemotherapy and radiation within 3 months prior to breast biopsy procedure.

Breastfeeding within 3 months.

Pregnancy (determined by urine dipstick).

A suspicious unbiopsied lesion by physical examination or mammography of the breast(s)
which is being studied.

Bleeding disorder.

Warfarin, low molecular weight heparin, or heparin use.

History of bilateral breast radiation.