Inclusion Criteria:

- Female patients with histologically confirmed incident invasive breast cancer (T1-4)
with positive hormone receptor status (ER and/or PgR positive) and no evidence of
regional lymph node metastasis (N0) or distant metastasis (M0)

- Patient has undergone complete primary tumor resection and axillary lymph node
dissection less than 90 days before start of study drug treatment.

- Patient is premenopausal at diagnosis of breast cancer (spontaneous and regular
menses with premenopausal estradiol levels (>10 ng/dL)

- Patient receives adjuvant standard chemoendocrine or endocrine therapy

- Bone density at study entry > -2.5 T-Score

Exclusion Criteria:

- History of treatment or disease affecting bone metabolism (e.g., Paget's disease,
primary hyperparathyroidism), prior treatment with bisphosphonates or treatments for
osteoporosis in addition to calcium and vitamin D

- Abnormal renal function

- Current active dental problems including infection of the teeth or jawbone (maxilla
or mandibular); dental or fixture trauma, or a current or prior diagnosis of
osteonecrosis of the jaw (ONJ), of exposed bone in the mouth, or of slow healing
after dental procedures, recent (within 6 weeks) or planned dental or jaw surgery
(e.g. extraction, implants)

- Pregnancy or lactation

- Women of childbearing potential not applying a medically recognized form of
contraception (i.e., oral contraceptives or implants, IUD, vaginal diaphragm or
sponge, or condom with spermicide)

Other protocol-defined inclusion/exclusion criteria may apply