Inclusion Criteria:

- Women willing and able to give written informed consent

- Pre-menopausal women with regular menstrual cycles (4 cycles in the past 6 months)

- At least 35 years of age

- Women at increased risk of developing breast cancer, defined as at least one of the
following four criteria:

- Having had a biopsy demonstrating atypical hyperplasia or lobular neoplasia/LCIS

- A germline mutation in BRCA1/2 in themselves or their family.

- A Gail Model Risk of > 1.67% over 5 years

- A strong family history of breast and/or ovarian cancer which is defined as at
least one of the following:

- One first-degree relative with breast cancer before the age of 50 years

- One first degree relative with bilateral breast cancer

- Two or more first-degree relatives with breast cancer

- One first degree relative and two or more second or third degree relatives
with breast cancer

- One first-degree relative with breast cancer and one or more relatives with
ovarian cancer

- Two second or third degree relatives with either breast cancer and one or
more with ovarian cancer

- One second or third degree relative with breast cancer and two or more with
ovarian cancer

- Three or more second or third degree relatives with breast cancer

- A prior history of breast cancer, including DCIS and stage 0-IIIb, and are at
least one year off of all therapy (including radiation, biologic, hormonal
and/or chemotherapy)

Exclusion Criteria:

- Women with a prior history of stage IV breast cancer or ovarian cancer

- Women already taking statins. Women previously on statins may participate if they
have not taken any statins in the six months prior to study entry

- Women concurrently participating in another breast cancer chemoprevention trial

- Women taking hormone replacement therapy (estrogen and progesterone; topical estrogen
will be allowed)

- Women taking tamoxifen, raloxifene, or an aromatase inhibitor

- Women taking drugs that increase risk of statin induced myopathy or rhabdomyolysis
(i.e., Niacin, protease inhibitors, verapamil, gemfibrozil, cyclosporine,
clofibrate/fenofibrate or any CYP3A4 inhibitor)

- Women with underlying liver disease or abnormal liver studies including:

- alkaline phosphatase, ALT, AST and Bilirubin (greater than 1.5 times normal)

- Women who have had hypersensitivity to atorvastatin or any component of the
formulation

- Women who are pregnant, planning pregnancy within the next year, or breastfeeding