Safety and Efficacy of Hormone Therapy With Letrozole in Postmenopausal Women With Breast Cancer

Inclusion criteria

• Postmenopausal women able to comply with the protocol requirements with confirmed primary invasive breast cancer whose tumours are estrogen-and/or progesterone-receptor positive
• Clinical stage T2 or >T2 tumours which in the investigators' opinion would not be eligible for breast-conserving surgery. The nodal status will be evaluated by palpation and/or ultrasound.
• Postmenopausal status defined by one of the following:

• Women with an intact uterus AND

• ≥ 55 years of age, OR
• < 55 years of age without menses for the last 5 years, OR
• < 55 years of age and have not had menses for at least the last 12 months (but have had menses in the last 5 years) and have postmenopausal levels of follicle-stimulating hormone.
• Women without an intact uterus AND

• ≥ 55 years of age, OR
• < 55 years of age and postmenopausal levels of follicle-stimulating hormone
• Both ovaries removed (prior to the diagnosis of breast cancer).
• Tumour measurable by clinical examination, mammography and ultrasound
• Adequate bone marrow function as shown by:

• WBC ≥ 3.5 x 10^9/L
• ANC ≥ 1.5 x 10^9/L
• Platelets ≥ LLN
• Hb > 10 g/dL

Exclusion criteria

• Multifocal disease (cancer that starts in several different sites)
• Patients with bilateral breast tumours.
• Patients who are eligible for breast conserving surgery.
• Evidence of inflammatory breast cancer or distant metastasis.
• Simultaneous anti-cancer treatments such as chemotherapy, immunotherapy/biological response modifiers, endocrine therapy (including steroids), bisphosphonate therapy and radiotherapy. NOTE: Bisphosphonate therapy for osteoporosis is NOT excluded, and can be continued. Patients who have received hormone replacement therapy will NOT be excluded if it is discontinued at least 2 weeks before starting the study.

The following additional treatments are NOT allowed during the treatment phase of the study:

• Any other anti-cancer therapy
• Hormone replacement therapy.
• Estrogen cream (including any intra-vaginal preparation).
• Steroids other than creams or inhalers.
• Megestrol acetate for the treatment of hot flushes.
• Radiation therapy.

Other protocol-defined inclusion/exclusion criteria may apply.