Intraoperative Radiation Therapy in Treating Patients With Breast Cancer Undergoing Breast-Conserving Surgery

Exclusion Criteria

• •Axillary lymph node positive breast cancer
• •Tumor size \> 3.5 cm
• •Extensive intraductal component (EIC \>= 25% of the lumpectomy specimen involved with ductal carcinoma in situ), as assessed on surgical pathologic lumpectomy specimen
• •Multicentric cancer in the same breast as diagnosed by clinical examination, mammography, ultrasound; magnetic resonance imaging (MRI) or pathologic assessment, not amenable to excision with negative margins with a single lumpectomy
• •Inability to assess pathologic margin status
• •Synchronous bilateral breast cancer at the time of diagnosis
• •Ipsilateral breast had a previous cancer and/or prior in-field radiation
• •Patients known to have BRCA1/2 gene mutations (testing for gene mutations is not required)
• •Patients undergoing primary systemic treatment (hormones or chemotherapy) as initial treatment with neoadjuvant reducing tumor size
• •Previous history of malignant disease does not preclude entry if the expectation of relapse-free survival at 10 years or greater
• •* Patients under the age of 50
• •* Estrogen receptor negative (as defined in Treatment Policy under "Pathology")
• •* Human epidermal growth factor receptor 2 (HER2) positive (as defined in Treatment Policy under "HER2")
• •* Lymphovascular invasion
• •* High grade
• •* Tumors \> 3 cm
• •* Node positive patients
• •* Prior chemotherapy or hormone therapy