An Open Label, Randomised, Parallel Group, Multicentre Study to Compare ZOLADEX 10.8 mg Given Every 12 Weeks With ZOLADEX 3.6 mg Given Every 4 Weeks in Pre-menopausal Women With Oestrogen Receptor Positive Advanced Breast Cancer

INTERVENTION: investigational material(s) Generic name etc : ZD9393 INN of investigational material : Therapeutic category code : 429 Other antitumor agents Dosage and Administration for Investigational material : 10.8 mg, one subcutaneous depot injection once every 12 weeks control material(s) Generic name etc : ZD9393 INN of investigational material : Therapeutic category code : 429 Other antitumor agents Dosage and Administration for Investigational material : 3.6 mg, one subcutaneous depot injection once every 4 weeks CONDITION: Breast Cancer INCLUSION CRITERIA: ‐ Female 20 years or older and pre‐menopausal. Pre‐menopausal defined as 1) last menses within 1 year of randomisation, and 2) E2 10 pg/mL or more, and FSH 30 mIU/mL or less within 4 weeks of randomisation. For patients who have had a hysterectomy, it is acceptable to meet only 2) ‐ Hormone sensitivity (ER positive) of primary or secondary tumour tissue. ‐ Histological/cytological confirmation of breast cancer and are candidates to receive hormonal therapy as therapy for advanced breast cancer.