Inclusion Criteria

DISEASE CHARACTERISTICS:

- At increased risk of developing breast cancer and enrolled on clinical trial
CAN-NCIC-MAP3

- Bone mineral density (BMD) (as measured by dual x-ray absorptometry [DEXA] scans
within 12 months prior to randomization to the core protocol [MAP.3]) T score > -2.0
standard deviation (i.e., 2.0 standard deviations below the average peak BMD of a
young adult woman) of spine (L1-L4) and total hip

- Serum for bone biomarkers (i.e., serum N-telopeptide and serum amino-terminal
procollagen 1 extension peptide) must have been obtained within 8 weeks prior to
registration to the study

PATIENT CHARACTERISTICS:

- Postmenopausal, defined as one of the following:

- Over 50 years of age with no spontaneous menses for at least 12 months before
study entry

- 50 years of age or under with no menses (spontaneous or secondary to
hysterectomy) for at least 12 months before study entry AND with
follicle-stimulating hormone level within postmenopausal range

- Underwent prior bilateral oophorectomy

- Available for collection of serum samples and BMD (DEXA) scans at the protocol
defined times (i.e., have BMD scans at years 2 and 5 at the same site)

- No history of fragility fractures (i.e., a broken bone that occurs with a fall from a
standing height or lesser amount of trauma)

- No malabsorption syndrome (e.g., untreated celiac disease, clinically relevant
vitamin D deficiency, or active hyper- or hypoparathyroidism)

- No Paget disease or other metabolic bone diseases (e.g., osteomalacia or osteogenesis
imperfecta)

- No Cushing disease or other pituitary diseases

- No inflammatory disease(s) (e.g., inflammatory bowel disease, rheumatoid arthritis,
lupus, psoriasic arthritis, ankylosing spondylitis, or autoimmune hepatitis)

PRIOR CONCURRENT THERAPY:

- More than 3 months since prior bone drugs, such as bisphosphonates, teriparatide
(parathyroid hormone [PTH]), sodium fluoride, calcitonin (Miacalcin®), strontium, or
high-dose vitamin D (i.e., vitamin D3 > 2,000 IU/day or calcitriol)

- No prior bisphosphonate therapy duration of more than 6 months total during lifetime

- No concurrent anabolic or chronic oral corticosteroids (the equivalent of 5 mg of
prednisone a day or higher for more than 2 weeks within the past 6 months and will
likely require ongoing therapy)

- Concurrent inhaled steroids allowed

- No concurrent medication that may have an effect on study endpoints for this study,
including any of the following:

- Anticonvulsants

- Sodium fluoride at daily doses > 5 mg/day for a period exceeding 1 month

- Anabolic steroids

- Teriparatide (parathyroid hormone)

- Bisphosphonates, except for women who develop osteoporosis while on this study;
these patients may be advised to start bone medication (i.e., strontium,
calcitonin, or high-dose Vitamin D (i.e., Vitamin D3 > 2000 IU/day or
calcitriol) at the discretion of their physician