Breast-Conserving Surgery Followed by Radiation Therapy With MRI-Detected Stage I or Stage II Breast Cancer

You may be eligible if

• Inclusion
• Patients with multicentric carcinoma (tumors in different quadrants of the breast or tumors separated by at least 4 cm)
• All radiographically suspicious lesions must be biopsied and have histologically confirmed ductal carcinoma in-situ, invasive ductal, invasive lobular, medullary, papillary, colloid (mucinous), or tubular histologies
• A maximum of two radiographically detected malignant lesions
• Clinical Stage I-II breast carcinoma, with lesion size =\< 5 cm for the dominant mass and the second lesion detected only on MRI, treated with lumpectomies; the MRI detected lesion must be pathologically =\< 1 cm
• Axillary lymph node evaluation, either sentinel lymph node biopsy or axillary dissection as deemed appropriate by the treating surgeon for all patients with invasive cancer; no axillary lymph node sampling is needed for patients with DCIS
• Negative resection margins with at least a 2 mm margin from invasive and in-situ cancer or a negative re-excision
• A posterior margin =\< 2 mm from DCIS is permissible provided fascia was taken
• Patients are eligible regardless of estrogen receptor, progesterone receptor, or Her-2/neu amplification
• Hormonal therapy is allowed; if adjuvant chemotherapy is planned, the chemotherapy should be delivered first and radiation must begin no earlier than three weeks and no later than eight weeks following completion of chemotherapy
• Signed study-specific informed consent prior to study entry
• Exclusion
• Extensive intraductal component by the Harvard definition (i.e., more than 25% of the invasive tumor is DCIS and DCIS present in adjacent breast tissue)
• Palpable or radiographically suspicious contralateral axillary, ipsilateral or contralateral supraclavicular, infraclavicular, or internal mammary lymph nodes unless these are histologically confirmed negative
• Patients receiving neoadjuvant chemotherapy
• Patients with distant metastatic disease detected by radiographic imaging; specific studies for systemic imaging should be obtained as directed by localized symptoms or per available NCCN guidelines
• Patients with known BRCA 1/BRCA 2 mutations or those with predicted risk of carrying the mutation by BRCAPRO (44) risk assessment \>= 50%
• Diffuse calcifications throughout the breast
• Patients with skin involvement or inflammatory breast cancer
• Patients with Paget's disease of the nipple
• Patients nonepithelial breast malignancies such as lymphoma or sarcoma
• Patients with collagen vascular disorders, specifically systemic lupus erythematosis, scleroderma, or dermatomyositis
• Patients with psychiatric, neurologic, or addictive disorders that would preclude obtaining informed consent
• Other malignancy, except non-melanomatous skin cancer, \< 5 years prior to participation in this study
• Patients who are pregnant or lactating, due to potential fetal exposure to radiation and unknown effects of radiation on lactating females