This is a prospective open-label one-arm phase III trial designed to evaluate the safety and efficacy of letrozole 2.5 mg administered orally daily for 24 months as adjuvant therapy in postmenopausal patients with primary breast cancer.

This trial is not recruiting patients in the United States.

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.