Optimal treatment of multiple ipsilateral primary breast cancers

Introduction The success of breast-conservation therapy (BCT) for patients with multiple ipsilateral invasive breast cancers (MIBC) is sparsely documented. Methods A retrospective review of single-institution experience. Patients with 2 or more invasive cancers separated by normal breast tissue were included; patients with 1 invasive cancer with additional in situ lesions and those receiving neoadjuvant therapy were excluded. Results One hundred forty-nine patients were treated over 19 years. Fifty-eight (39%) patients underwent BCT. Preoperatively, multiple tumors were suspected in more mastectomy patients than BCT patients (75% versus 62%). Most patients had 2 tumors and 1 histology. Fifty-five percent of patients with tumors within 1 quadrant underwent BCT versus 10% of patients with tumors in more than 1 quadrant. One hundred eight patients underwent sentinel lymph node (SLN) biopsy. Twenty-seven percent (34) were SLN positive. There were no regional recurrences among the SLN-negative patients. Six patients recurred: 1 nodal, 1 local, and 4 distant. The locoregional BCT recurrence rate was 3.4%. Discussion MIBC patients can safely undergo BCT with low recurrence risk. SLNB can be performed with minimal risk of regional recurrence.