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

OBJECTIVES: Primary * To assess the local recurrence (LR) rate with breast-conservation in patients with multiple ipsilateral primary breast cancer (MIBC). Secondary * To examine the conversion rate to mastectomy secondary to persistent positive margins; poor cosmesis within the first year of attempting breast-conservation surgery (BCS) or inability to satisfy the radiation dose constraints on the boost to the lumpectomy bed of each site of disease. * To assess whether patients who did not undergo re-excision for close margins (\< 2 mm) have a higher local recurrence (LR) rate than patients for whom negative margins were achieved. * To assess patient's perception of cosmesis and incidence of breast lymphedema. * To assess incidence of breast lymphedema * To examine the type and severity of adverse effects of breast conserving surgery and radiation for women with multiple ipsilateral primary breast cancer (MIBC). * To examine the radiation-related side effects of whole-breast radiation with a boost to 1 large or \> 1 lumpectomy site. OUTLINE: This is a multicenter study. Patients undergo breast-conserving surgery (BCS) with all lesions resected to negative margins using 1 lumpectomy or 2-3 separate lumpectomy incisions at the discretion of the surgeon. Patients receive adjuvant chemotherapy and/or endocrine therapy at the discretion of the treating medical oncologist based on tumor characteristics.