Capecitabine and Pegylated Interferon Alfa-2a in Treating Patients With Recurrent or Progressive Brain Metastases Due to Breast Cancer

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed breast cancer that metastasized to the brain, meeting all of the following criteria:
• Must have ≥ 1 inoperable brain metastases, meeting 1 of the following criteria:
• Progressive or recurrent disease after prior whole-brain or stereotactic radiotherapy
• Ineligible for OR unwilling to be treated with radiotherapy
• At least 1 unidimensionally measurable brain metastasis by enhanced MRI within the past 21 days
• No progression or development of central nervous system (CNS) metastasis during prior treatment with capecitabine, fluorouracil, interferon alfa, or interferon beta
• Systemic (i.e., outside the CNS system) cancer must be stable
• No progressive disease (e.g., liver, lymphangitic, or lung metastases)
• Hormone receptor status:
• Not specified

PATIENT CHARACTERISTICS:

Age

• 18 and over

Sex

• Male or female

Menopausal status

• Not specified

Performance status

• Karnofsky 70-100%

Life expectancy

• More than 12 weeks

Hematopoietic

• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• Hemoglobin ≥ 10 mg/dL
• No history of idiopathic thrombocytopenic purpura
• No known uncontrolled coagulopathy
• No increased risk for anemia (e.g., thalassemia or spherocytosis)
• No medically problematic anemia

Hepatic

• aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT) ≤ 2.5 times upper limit of normal (ULN) (5 times ULN for patients with concurrent liver metastases )
• Bilirubin ≤ 1.5 times ULN
• Alkaline phosphatase ≤ 2.5 times ULN (5 times ULN for patients with concurrent liver metastases; 10 times ULN for patients with concurrent bone metastases)

Renal

• Creatinine ≤ 1.5 times ULN OR
• Creatinine clearance ≥ 30 mL/min

Cardiovascular

• No congestive heart failure
• No symptomatic coronary artery disease
• No medically uncontrolled arrhythmia
• No other clinically significant cardiac disease
• No myocardial infarction within the past 12 months

Gastrointestinal

• No history of inflammatory bowel disease
• Must have intact upper gastrointestinal tract
• Able to swallow tablets
• No malabsorption syndrome
• No history of gastrointestinal bleeding

Immunologic

• No prior unanticipated severe reaction to fluoropyrimidine therapy, interferon, pegylated interferon, or a pegylated moiety
• No known sensitivity to fluorouracil
• No serious uncontrolled infection
• No history of immunologically mediated disease

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 6 months after completion of study treatment
• No known dihydropyrimidine dehydrogenase deficiency
• No history of depression characterized by a suicide attempt
• No history of hospitalization for psychiatric disease
• No history of other severe psychiatric disease
• No prior disability as a result of psychiatric disease
• No history of clinically significant psychiatric disability that would preclude study compliance
• No other malignancy within the past 5 years except cured nonmelanoma skin cancer or treated carcinoma in situ of the cervix
• No uncontrolled thyroid dysfunction (e.g., thyroid-stimulating hormone not in normal range)
• No evidence of severe retinopathy (e.g., Cytomegalovirus (CMV) retinitis or macular degeneration)
• No clinically relevant ophthalmologic disorders due to diabetes or hypertension
• No other serious uncontrolled medical conditions that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• See Disease Characteristics
• At least 3 months since prior interferon alfa or interferon beta

Chemotherapy

• See Disease Characteristics
• At least 3 months since prior capecitabine or fluorouracil

Endocrine therapy

• Concurrent hormonal agents (e.g., tamoxifen, raloxifene, or anastrazole) for breast cancer allowed

Radiotherapy

• See Disease Characteristics

Surgery

• More than 4 weeks since prior major surgery and recovered

Other

• More than 4 weeks since prior participation in another investigational drug study
• At least 4 weeks since prior and no concurrent brivudine or sorivudine
• No concurrent cimetidine
• No other concurrent investigational or commercial agents or therapies for this malignancy