DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed metastatic infiltrating carcinoma of the breast

• Meets one of the following criteria for newly diagnosed disease:

  • Newly diagnosed with metastatic breast cancer

    • No prior chemotherapy for metastatic disease

  • Known to have breast cancer

    • More than 18 months since prior adjuvant chemotherapy or radiotherapy for nonmetastatic or metastatic disease

• CEA > 5 OR positive by standard immunohistochemistry

  • Positivity defined as more than 30% of cells staining
• Measurable or evaluable disease or no evidence of disease (postsurgery)
• No brain metastases

• Hormone receptor status:

  • Positive or negative

PATIENT CHARACTERISTICS:

Age

• 18 and over

Sex:

• Not specified

Menopausal status:

• Not specified

Performance status

• Karnofsky 70-100% OR
• ECOG 0-1

Life expectancy

• At least 6 months

Hematopoietic

• Absolute neutrophil count > 1,000/mm^3
• Platelet count > 90,000/mm^3
• No history of abnormal bleeding tendency

Hepatic

• Bilirubin < 1.5 mg/dL* (except in patients with Gilbert's disease)
• AST and ALT < 3 times upper limit of normal*
• Hepatitis B and C negative NOTE: *Except if due to tumor involvement of the liver prior to induction therapy

Renal

• Urinalysis normal

  • If proteinuria is present, must be < 1 g by 24-hour urine collection
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• Ejection fraction normal by MUGA or 2D echocardiogram

  • If ejection fraction is between 35% and 45%, increase of ejection fraction with stress must be estimated at 10% or more
• No clinically significant cardiomyopathy requiring treatment

• None of the following:

  • Cardiomyopathy or symptomatic congestive heart failure
  • Symptomatic arrhythmia that is not controlled by medication
  • Unstable coronary artery disease (i.e., unstable angina that require active intervention)
  • Recent infarction or cerebrovascular accident within the past 6 months

Pulmonary

• Corrected DLCO > 50%

Immunologic

• No prior or active eczema or other eczematoid skin disorders
• No predisposition to repeated infections
• No allergy to eggs or egg products
• No history of allergy or complications with prior vaccinia vaccination

• No autoimmune disease, including any of the following:

  • Autoimmune neutropenia, thrombocytopenia, or hemolytic anemia
  • Rheumatoid arthritis
  • Systemic lupus erythematosus
  • Sjögren's syndrome
  • Scleroderma
  • Systemic sclerosis
  • Myasthenia gravis
  • Multiple sclerosis
  • Goodpasture syndrome
  • Addison's disease
  • Hashimoto's thyroiditis
  • Active Graves' disease

• No abnormality of any of the following tests:

  • Antinuclear antibody
  • Anti-DNA
  • T3, T4, and thyroid-stimulating hormone* NOTE: *Patients with endocrine disease that is controlled by replacement therapy including diabetes, thyroid and adrenal disease or vitiligo are eligible
• No immunodeficiency or immunosuppression by disease or therapy
• HIV negative

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during study therapy
• No active inflammatory bowel disease

• No acute, chronic, or exfoliative skin conditions, including any of the following:

  • Atopic dermatitis
  • Burns
  • Impetigo
  • Varicella zoster
  • Severe acne
  • Other open wounds or rashes
• No history of seizures
• No history of encephalitis
• No other active malignancy except treated skin cancer or carcinoma in situ
• No unacceptable medical or psychiatric risk
• No urgent or emergent clinical situation that would preclude study participation

• Must be able to avoid close household contact for at least 2 weeks after vaccination with the following individuals:

  • Pregnant or nursing women
  • Children under 3 years of age
  • Individuals who are immunodeficient or immunosuppressed by disease or therapy (including HIV infection)

  • Individuals with the following conditions:

    • Prior or active eczema or eczematoid skin disorders
    • Other acute, chronic, or exfoliative skin conditions (e.g., atopic dermatitis, burns, impetigo, varicella zoster, severe acne, or other open rashes or wounds)

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics

Endocrine therapy

• Prior hormonal therapy for stage IV disease allowed

  • Disease progression on hormonal therapy alone allowed
• No concurrent chronic corticosteroids

Radiotherapy

• See Disease Characteristics

Surgery

• See Disease Characteristics
• No prior splenectomy

Other

• No concurrent chronic immunosuppressive therapy