Inclusion Criteria:

- Postmenopausal females, defined as one from the next :

1. Natural menopause >/=1 year,

2. Surgical ovariectomy,

3. Chemotherapy-induced amenorrhoea >/=2 years.

- Patients who have had surgical treatment for histological confirmed breast cancer
that was non-metastatic at the time of the initial diagnosis.

- Patients who are disease-free after 2 or 3 years of adjuvant tamoxifen treatment.

- Patients whose tumour was estrogen receptor positive (ER+).

- Evidence of a personally signed and dated informed consent document indicating that
the subject (or a legally acceptable representative) has been informed of all
pertinent aspects of the study.

Exclusion Criteria:

- Patients for whom Aromasin® treatment is contraindicated (see SmPC).

- Presence of metastasis or a contra lateral tumour.

- Other adjuvant endocrine therapy.

- Another concomitant antineoplastic treatment

- Participation in a clinical trial with an investigational drug during the 30 days
prior to enrolment in the study.

- The patients are not supposed to participate to any other trial during all the study
period.