The sequential administration of endocrine therapies to patients with advanced breast cancer requires the availability of therapies with different modes of actions, so that tumours developing resistance to one agent are not cross resistant to another. Because of its mechanism of action, fulvestrant is distinct from other hormonal therapies, which therefore limits the possibility of cross-resistance with other therapies such as tamoxifen and the aromatase inhibitors (AIs)

• In this way, patients may benefit from an extended period of endocrine treatment, which has considerable tolerability and quality-of-life advantages over cytotoxic chemotherapy.
• In Belgium, fulvestrant is indicated for treating postmenopausal women with hormone receptor-positive locally advanced or metastatic breast cancer with recurrence during or after adjuvant anti-oestrogen therapy or disease progression during anti-oestrogen treatment. However, little information is currently available on how fulvestrant is actually being used by physicians in Belgium. The optimum sequence of endocrine treatment for advanced breast cancer has yet to be defined and may depend on certain patient or disease characteristics.

Fulvestrant has been granted reimbursement by the Belgian Health authorities (RIZIV/INAMI) with the recommendation to collect the real life data necessary to assess the patients' breast cancer treatment history that may influence the actual endocrine treatment sequence according to physicians current clinical practice..

Inclusion Criteria:

• Postmenopausal women with hormone receptor-positive locally advanced or metastatic breast cancer

Exclusion Criteria:

Woman with post-menopausal breast cancer.