Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed advanced breast cancer that is refractory or unlikely to
respond to hormonal therapy AND failed at least 1 prior chemotherapy regimen

- Symptomatic lymphangitic pulmonary dissemination allowed

- Extensive visceral metastasis allowed

- Patients who are refractory or who have failed to respond after at least 8 weeks of
methotrexate or a methotrexate-containing regimen are not eligible

- Measurable disease

- No bone metastases

- Hormone receptor status:

- Estrogen receptor negative

PATIENT CHARACTERISTICS:

Age:

- Postmenopausal

Sex:

- Female

Menopausal status:

- Postmenopausal

Performance status:

- Karnofsky 60-100%

Life expectancy:

- At least 3 months

Hematopoietic:

- WBC at least 3,000/mm^3

- Platelet count at least 100,000/mm^3

Hepatic:

- Bilirubin no greater than 2.5 mg/dL

- SGOT no greater than 2 times normal

- Blood ammonia normal

- No hepatic failure

Renal:

- BUN less than 60 mg/dL

- Creatinine no greater than 2.5 mg/dL

- Creatinine clearance greater than 60 mL/min

- No chronic renal failure

Cardiovascular:

- No severe heart disease

Pulmonary:

- No severe lung disease

Other:

- No serious active infections or fever

- No other concurrent serious disease

- No prior or concurrent secondary malignancies within the past 2 years

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- At least 4 weeks since prior immunotherapy and recovered

- No concurrent biologic therapy for metastatic breast cancer

Chemotherapy:

- See Disease Characteristics

- At least 4 weeks since prior cytotoxic chemotherapy and recovered

- No other concurrent chemotherapy for metastatic breast cancer

Endocrine therapy:

- See Disease Characteristics

- At least 4 weeks since prior hormonal therapy and recovered

- No concurrent hormonal therapy for metastatic breast cancer

Radiotherapy:

- At least 4 weeks since prior radiotherapy and recovered

- No concurrent radiotherapy for metastatic breast cancer

Surgery:

- Not specified

Other:

- At least 4 weeks since prior participation in experimental clinical trials

- No prior antineoplaston A10 therapy

- No other concurrent treatment for metastatic breast cancer

- No concurrent salicylates, nonsteroidal anti-inflammatory drugs, phenylbutazone,
phenytoin, and sulfonamides