DISEASE CHARACTERISTICS:

• Histologically proven invasive carcinoma of the breast

  • No evidence of T4, N2-3, or M1 disease prior to surgery
  • Node positive or high-risk node negative

• Prior breast-conserving therapy (BCT) (e.g., lumpectomy, partial mastectomy, or segmental mastectomy) and axillary node dissection or sentinel node biopsy required and must be a candidate for breast radiotherapy after BCT

  • Normally patients should have microscopically clear resection margins and those with positive margins should undergo reexcision
  • Patients with microscopically focally positive margins (defined as no greater than 3 times high power fields) are candidates for breast radiotherapy plus a boost to the lumpectomy site

  • Patients with prior sentinel node dissection eligible if node negative, but still meet high-risk criteria

    • If node positive, then a level I and II axillary dissection must be performed
  • No evidence of residual disease in axilla after dissection
• Must be treated with currently accepted adjuvant systemic chemotherapy and/or hormonal therapy

• High risk of regional and systemic recurrence due to one of the following:

  • Pathologically positive axillary lymph nodes

  • Pathologically negative axillary lymph nodes with one of the following:

    • Primary tumor greater than 5 cm

    • Primary tumor greater than 2 cm and less than 10 axillary lymph nodes excised and one of the following:

      • Estrogen receptor negative
      • Skarf-Bloom-Richardson grade 3
      • Lymphovascular invasion

• Hormone receptor status:

  • Estrogen and progesterone receptor status known

PATIENT CHARACTERISTICS:

Age:

• 16 and over

Sex:

• Female

Menopausal status:

• Premenopausal or postmenopausal

Performance status:

• ECOG 0-2

Life expectancy:

• At least 5 years

Hematopoietic:

• Not specified

Hepatic:

• SGOT and/or SGPT no greater than 3 times upper limit of normal (ULN)*
• Alkaline phosphatase no greater than 3 times ULN* NOTE: * Patients with laboratory values greater than 3 times ULN may still be eligible if no metastatic disease by imaging examinations

Renal:

• No serious nonmalignant renal disease

Cardiovascular:

• No serious nonmalignant cardiovascular disease

Pulmonary:

• No serious nonmalignant pulmonary disease

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No other serious nonmalignant disease (e.g., systemic lupus erythematosus or scleroderma) that would preclude definitive surgery or radiotherapy

• No other malignancy except:

  • Nonmelanomatous skin cancer
  • Carcinoma in situ of the cervix or endometrium
  • Contralateral noninvasive breast cancer (unless prior radiotherapy to the contralateral breast)
  • Invasive carcinoma of the cervix, endometrium, colon, thyroid, or melanoma that was curatively treated at least 5 years prior to study participation
• No psychiatric or addictive disorder that would preclude informed consent or study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• Concurrent standard adjuvant chemotherapy allowed

Endocrine therapy:

• See Disease Characteristics
• Concurrent standard adjuvant hormonal therapy allowed

Radiotherapy:

• See Disease Characteristics

Surgery:

• See Disease Characteristics