The influence of additional surgical margins on the total specimen volume excised and the reoperative rate after breast-conserving surgery.

BACKGROUND: It is unclear whether the additional removal of breast tissue during breast-conserving therapy (BCT) for breast cancer beyond the standard lumpectomy reduces the incidence of inadequate microscopic margins found at pathological examination and subsequent reoperation. This study compares the reoperative rates after initial BCT in 3 groups of patients who underwent lumpectomy with complete resection of 4 to 6 additional margins, lumpectomy with selective resection of 1 to 3 additional margins, or standard lumpectomy.
METHODS: Retrospective data were reviewed from 171 selected cases of BCT, from May 2000 to February 2006. Forty-five cases involved lumpectomy with complete resection of 4 to 6 additional margins; 77 involved lumpectomy with selective resection of 1 to 3 additional margins, whereas 49 involved standard lumpectomy. All samples underwent pathologic analysis of inked resection margins by permanent section. The 3 groups were compared for patient demographics, tumor size and histologic subtype, tumor stage, margin status, excised specimen volume, and eventual subsequent reoperation. Adequate surgical margin was defined as any negative margin greater than 2 mm.
RESULTS: The group with complete resection of 4 to 6 additional margins had a subsequent reoperation rate of 17.7%, whereas the group with selective resection of 1 to 3 additional margins and the standard lumpectomy group had a subsequent reoperation rate of 32.5% and 38.7%, respectively, because of inadequate margins. The mean total excised specimen volume in the 3 groups was 129.19, 46.04, and 37.44 cm3, respectively.
CONCLUSIONS: The complete resection of 4 to 6 additional margins during the initial BCT resulted in the lowest subsequent reoperation rate, and the largest total volume specimen excised among the 3 techniques studied.