The main purpose of this study is to see what levels of Bone Mineral Density post-menopausal women with breast cancer have, and to see if the level of Bone Mineral Density changes during a women's treatment after her surgery.

This trial studies changes in Bone Mineral Density and markers of of bone activity in post-menopausal women receiving treatment for early stage breast cancer.

Inclusion Criteria:

• Documented diagnosis of breast cancer
• Last menstrual period occurring more than 5 years ago
• Non-metastatic breast cancer tumor with the diagnosis of Tis, Tl-T4, N0-3, M0
• DCIS is allowed, but LCIS (only) is not

Exclusion Criteria:

• Any metabolic bone disease other than postmenopausal osteoporosis or osteopenia
• Use of systemic gonadal hormonal medications or supplements within the past 24 months
• Prior use of tamoxifen or raloxifene is permitted if the medication was discontinued more than 24 months prior to the diagnosis of breast cancer.
• No adjuvant antiestrogen, antineoplastic, therapies are permitted on study.
• Chronic use of systemic steroids for disease process other than breast cancer chemotherapy premedication or antiemetics
• History of rheumatoid arthritis, ankylosing spondylitis, hyperparathyroidism, renal osteodystrophy, moderate to severe inflammatory or autoimmune disease or newly diagnosed thyroid condition requiring titration of medications.
• Lobular carcinoma in situ or Stage IV breast cancer and patients with a concurrently active second malignancy other then adequately treated non-melanoma skin cancers or in situ cervical cancer.
• participation in other clinical trials that are measuring BMD as a study parameter
• Patients with conditions that are expected to distort BMD reading and make DEXA results unreliable
• Patients with concurrent medical or psychiatric conditions that would keep them from understanding and complying with this clinical trial.

Women with breast cancer