Breast-Conserving Surgery and Radiation Therapy in Treating Patients with Multiple Ipsilateral Breast Cancer

Inclusion Criteria

• Life expectancy of at least 5 years, excluding diagnosis of breast cancer (comorbid conditions should be taken into consideration, but breast cancer diagnosis is not a consideration)
• Men are excluded from this study
• Upon clinical exam and pre-operative imaging by mammogram +/- MRI, two or three foci of biopsy proven breast cancer separated by >= 2 cm of normal breast tissue; foci must include at least one focus of invasive breast carcinoma with another focus of either invasive breast carcinoma or ductal carcinoma in situ (DCIS); no more than 2 quadrants with biopsy proven breast cancer; Note: the shortest distance between lesions must be reported on mammogram +/- MRI and eligibility criteria must be met on both, if both are obtained; Note: patient is eligible for study if lesion is not visualized on all imaging modalities (i.e., any of the lesion [s] is/are visualized on MRI but not on mammogram OR visualized on mammogram but not on MRI); ultrasound cannot be used to determine patient eligibility; eligibility to be determined by bilateral mammogram +/- MRI only; fine needle aspirate of the second or third lesion to document malignancy is allowed if the first focus is shown to be invasive by core needle biopsy; patient may remain on study if, upon pathological assessment, two or three lesions identified on pre-operative imaging represent one contiguous lesion
• Patients may be registered AFTER surgery and PRIOR TO radiation therapy if either of the criteria is met: * An area of atypia > 2 cm from the index lesion excised at the time of cancer operation is upgraded to DCIS or invasive carcinoma thereby identifying MIBC OR * Patient underwent resection of two or three foci of malignancy by breast conservation surgery with a minimum of one invasive focus of breast cancer and a minimum of 2 cm of normal breast tissue between the lesions on final pathology
• Bilateral mammogram =< 90 days prior to date of surgery; Note: for patients undergoing more than 1 breast operation, this is the date of the first breast surgery for breast cancer treatment
• cN0 or cN1 disease
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, 1, or 2
• Ability to complete questionnaire(s) by themselves or with assistance
• Ability to provide written informed consent
• Willing to return to enrolling institution for follow-up during the Active Monitoring Phase (the active treatment and observation portions) of the study; patients are encouraged to return to the enrolling institution; however, patients may receive radiation therapy at a different institution other than the enrolling institution

Exclusion Criteria

• Any of the following: * Pregnant women * Nursing women * Women of childbearing potential who are unwilling to employ adequate contraception (as determined by the treating physician)
• Largest single focus of disease > 5 centimeters by either mammogram or MRI or both; Note: measurement of the largest single focus should include any satellite lesions within 1 centimeter of the index lesion
• Surgical axillary staging procedure prior to first definitive breast operation; Note: fine-needle aspiration (FNA) or core needle biopsy of axillary node is permitted
• Clinical or radiographic evidence of metastatic disease
• Prior history of ipsilateral breast cancer (DCIS, LCIS [lobular cancer in situ] or invasive)
• cNX, cN2, or cN3 disease
• Breast implants at time of diagnosis; Note: patients who have had implants previously removed prior to diagnosis are eligible
• Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would interfere significantly with whole-breast irradiation (such as connective tissue disorders, lupus, or scleroderma)
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Prior or current LCIS, DCIS or invasive breast cancer in the opposite breast (i.e., bilateral disease is not allowed)
• Treatment including radiation therapy, chemotherapy, biotherapy, or hormonal therapy for this cancer prior to surgery (i.e., any neoadjuvant chemotherapy or endocrine therapy is not allowed); patients who undergo surgical resection with breast conservation and then are treated with adjuvant systemic therapy are eligible to enroll prior to the start of radiotherapy
• Planned partial breast radiation
• Patients with known breast cancer (BRCA) mutations; patients who are not tested or whose testing result is not returned at the time of registration are not excluded from registering to this study
• Other active malignancy =< 5 years prior to registration; EXCEPTIONS: non-melanotic skin cancer or carcinoma-in-situ of the cervix; Note: if there is a history of prior malignancy, they must not be receiving other specific treatment for their cancer