Inclusion Criteria

Inclusion criteria:

- Compliant postmenopausal women with primary operable breast cancer after complete
surgery and suitable for endocrine treatment

- Nodal status negative or positive

- Good Health status 0-2 (Eastern Cooperative Oncology Group)

- Estrogen- and/or progesterone-receptor positive

- Adequate marrow, kidney and liver function

Exclusion criteria:

- Metastatic or inflammatory breast cancer

- Patients with previous or concomitant cancers (not breast cancer) within the past 5
years EXCEPT adequately treated basal or squamous cell skin cancer or in situ cancer
of the cervix. Patients with other previous cancers must have been disease-free for
at least 5 years and Patients with uncontrolled, non-malignant systemic
cardiovascular, kidney, and liver diseases.

- Current/active dental problems including infection of the teeth or jawbone, dental or
fixture trauma, or a current or prior diagnosis of osteonecrosis of the jaw, of
exposed bone in the mouth, or of slow healing after dental procedures.

- Recent (within 6 weeks) or planned dental or jaw surgery

- Patients with primary overactive parathyroid

- Patients with a known hypersensitivity to zoledronic acid or other bisphosphonates.