Gefitinib With or Without Tamoxifen in Treating Patients With Tamoxifen-Resistant Metastatic Breast Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed breast cancer
• * Metastatic disease
• Initial clinical benefit from tamoxifen for metastatic disease, defined by 1 of the following:
• * Stable disease for 24 weeks or longer
• * Objective tumor response
• Documentation of clinical progression on tamoxifen within the past 6 weeks
• Hormone receptor status:
• * Estrogen or progesterone receptor positive on most recently analyzed biopsy
• PATIENT CHARACTERISTICS:
• Age
• 18 and over
• Sex
• Not specified
• Menopausal status
• Not specified
• Performance status
• ECOG 0-2
• Life expectancy
• At least 6 months
• Hematopoietic
• Absolute neutrophil count ≥ 1,500/mm\^3
• Platelet count ≥ 100,000/mm\^3
• Hepatic
• AST ≤ 1.5 times upper limit of normal (ULN)
• Bilirubin ≤ 1.5 times ULN
• Renal
• Creatinine ≤ 1.5 times ULN OR
• Creatinine clearance ≥ 50 mL/min
• Pulmonary
• No clinically active interstitial lung disease
• * Patients with asymptomatic chronic stable radiographic changes are eligible
• Other
• Not pregnant or nursing
• Fertile patients must use effective contraception
• No known hypersensitivity to gefitinib
• No other malignancy within the past 5 years except basal cell carcinoma or carcinoma in situ of the cervix
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• No concurrent trastuzumab (Herceptin®)
• Chemotherapy
• No concurrent cytotoxic chemotherapy
• Endocrine therapy
• See Disease Characteristics
• At least 2 weeks since other prior tamoxifen
• No concurrent hormone replacement therapy
• No other concurrent antiestrogens, including raloxifene
• No concurrent aromatase inhibitors
• No concurrent megestrol
• Concurrent systemic steroids for reasons other than skin toxicity allowed provided the steroids were initiated before study entry AND dose remains stable
• Radiotherapy
• Concurrent palliative radiotherapy as short-term treatment for symptomatic bone metastases allowed provided other evaluable sites of disease are present AND treatment lasts no more than 14 days
• Surgery
• Recovered from prior oncologic or other major surgery
• No concurrent surgery during and for 7 days after study treatment
• No concurrent ophthalmic surgery
• Other
• Recovered from all prior therapy (except alopecia)
• More than 30 days since prior investigational drugs
• No other concurrent investigational agents
• No concurrent administration of any of the following:
• * Phenytoin
• * Carbamazepine
• * Barbiturates
• * Rifampin
• * Phenobarbital
• * Hypericum perforatum (St. John's wort)
• * Systemic retinoids
• * CYP3A4 inhibitors (e.g., itraconazole)
• * Drugs that cause significant sustained elevation in gastric pH ≥ 5