Partial Breast Irradiation for Patients Undergoing Breast Conservation Therapy for Early Stage Breast Cancer: A Pilot Study

Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed breast cancer, including the following histologic subtypes:

- Invasive ductal carcinoma

- Medullary ductal carcinoma

- Papillary ductal carcinoma

- Colloid (mucinous) ductal carcinoma

- Tubular ductal carcinoma

- The following histologic subtypes are not allowed:

- Invasive lobular carcinoma

- Extensive lobular carcinoma in situ

- Ductal carcinoma in situ (DCIS)

- Nonepithelial breast malignancies, such as lymphoma or sarcoma

- No extensive intraductal component by Harvard definition (i.e., more than 25% of the
invasive tumor is DCIS or DCIS present in adjacent tissue)

- Stage I or II disease (T1, N0; T1, N1a; T2, N0; or T2, N1a)

- Lesion ≤ 3 cm

- No more than 3 positive lymph nodes

- Patients with 4 or more positive axillary lymph nodes found at the time of
axillary lymph node dissection/sentinel lymph node biopsy are not eligible

- Has undergone tylectomy (lumpectomy) and axillary lymph node sampling (axillary node
dissection or sentinel node biopsy)

- Negative resection margins with ≥ 2 mm margin from invasive or in situ cancer OR
a negative re-excision margin

- Unifocal breast cancer

- No multicentric carcinoma (tumors in different quadrants of the breast or tumors
separated by ≥ 4 cm)

- No palpable or radiographically suspicious contralateral axillary,
ipsilateral or contralateral supraclavicular, infraclavicular, or internal
mammary lymph nodes unless these are histologically confirmed negative

- No skin involvement of disease

- No Paget's disease of the nipple

- No distant metastatic disease

- Hormone-receptor status not specified

PATIENT CHARACTERISTICS:

- Female

- Menopausal status not specified

- Not pregnant or lactating

- Negative pregnancy test

- Fertile patients must use effective contraception for ≥ 1 week prior to, during, and
for ≥ 2 weeks after completion of study treatment

- No collagen vascular disorders, specifically systemic lupus erythematosus,
scleroderma, or dermatomyositis

- No psychiatric, neurologic, or addictive disorders that would preclude obtaining
informed consent

- No other malignancy within the past 5 years, except non-melanomatous skin cancer

PRIOR CONCURRENT THERAPY:

- No prior radiotherapy to the breast

- No chemotherapy for at least 2 weeks before and 2 weeks after completion of study
radiotherapy

- Concurrent hormonal therapy allowed