The progression free survival and efficacy of 250 mg ZD1839 in combination with a fixed dose of fulvestrant 250 mg im once a month will be evaluated in female patients with histologically-confirmed advanced or metastatic, ER and/or PR positive breast cancer

Inclusion Criteria:

• Histologically confirmed advanced or metastatic breast cancer
• postmenopausal females with amenorrhoea > 12 months and an intact uterus
• FSH levels within postmenopausal range or have undergone a bilateral oophorectomy
• ER &/or PR positive
• previous adjuvant hormone therapy > 12 months prior to enrolment
• previous adjuvant chemotherapy > 6 months prior to enrolment
• measurable disease according to RECIST and/or non measurable bone disease
• life expectancy of at least 12 weeks
• World Health Organisation (WHO) performance status (PS) of 0 to 1.

Exclusion Criteria:

• Male
• life-threatening metastatic visceral disease
• evidence of clinically active interstitial lung disease
• ER and PR negative
• treatment with LHRH analogues < 3 months prior to enrolment
• patients who have restarted menses or do not have FSH levels within the postmenopausal range
• treatment with strontium - 90 (or other radio pharmaceutical) within the previous 3 months
• Treatment with hormonotherapy and/or chemotherapy for advanced disease
• extensive radiotherapy to measurable lesions within the last 4 weeks (i.e. >30% of bone marrow, e.g. whole of pelvis or half of spine)
• currently receiving oestrogen replacement therapy
• treatment with a non-approved or experimental drug within 4 weeks before enrolment
• absolute neutrophil count (ANC) less than 1.5 x 109/litre (L) or platelets less than 100 x 109/L , serum bilirubin greater than 1.25 times the upper limit of reference range (ULRR, serum creatinine greater than 1.5 mg/dL, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 2.5 times the ULRR if no demonstrable liver metastases, or greater than 5 times the ULRR in the presence of liver metastases, history of bleeding diathesis or long term or present anticoagulant therapy (other than antiplatelet therapy
• any unresolved chronic toxicity greater than CTC grade 2 from previous anticancer therapy
• concomitant use of phenytoin, carbamazepine, barbiturates, rifampicin, known
• severe hypersensitivity to ZD1839 or fulvestrant or any of the excipients of this product.