Inclusion Criteria:

- provision of informed consent

- histologically proven HR+ operable invasive breast cancer

- completion of surgery and chemotherapy(if given).

- women defined as pre- or perimenopausal according to all of the following: aged 50
years or younger, at least one menstrual period during the last months.

Exclusion Criteria:

- clinical evidence of metastatic disease

- pregnancy or breast-feeding

- bilateral oophorectomy;

- radiation of the ovaries

- patients who, for whatever reason(eg, confusion, infirmity,alcoholism),are unlikely
to comply with trial requirements

- patients whose chemotherapy was started more than 8 weeks after completion of primary
surgery or whose chemotherapy was completed more than 8 weeks before starting the
study treatment. Chemotherapy, if given, should have been given post-operatively, ie,
patients who received neoadjuvant chemotherapy are ineligible

- patients who have not received chemotherapy and whose primary surgery was completed
more than 8 weeks before starting the study treatment

- previous hormonal therapy as adjuvant treatment for breast cancer

- patients unwilling to stop taking any drug known to affect sex hormonal status, or in
whom it would be inappropriate to stop

- previous history of invasive malignancy within the last 5 years, other than squamous
or basal cell carcinoma of the skin or carcinoma in situ of the cervix, adequately
cone biopsied

- treatment with a non-approved or experimental drug during 1 month before entry into
the study

- history of hypersensitivity to active or inactive excipients of tamoxifen and Zoladex

- history of bleeding diathesis (ie. Disseminated intravascular coagulation, clotting
factor deficiency), or long term anticoagulant therapy (other than antiplatelet
therapy and low dose warfarin )

- leukopenia and/or thrombocytopenia

- history of ocular fundus diseases

- history of thromboembolic diseases