Value of intraoperative frozen section analysis in re-excision margin evaluation in breast-conserving surgery for cancer: a single institution experience

Previous studies have demonstrated that in women with breast cancer treated with breast-conserving surgery (BCS), intraoperative frozen section analysis of lumpectomy margins results in a decrease in reoperation rates for margin control. However, the value of intraoperative frozen margin evaluation (FME) in re-excision margin analysis was not fully understood. We conducted a retrospective review of patients who underwent attempted breast-conserving surgery for breast cancer with routine intraoperative frozen margin evaluation at our institution between January 1998 and May 2016. The number of frozen margin evaluation was analyzed. We additionally analyzed factors associated with positive re-excised margins to identify correlations with patient characteristics. A total of 760 patients who underwent attempted breast-conserving surgery were routinely conducted intraoperative frozen margin evaluation, frozen sections were obtained from the initial margin only in 82.5% (n = 627), the initial margin as well as a one-time re-excision analysis in 15.8% (n = 120), or the initial margin and two or more re-excision analyses in 1.7% (n-13). Based on the results of frozen margin evaluation, 727 (95.6%) of the patients underwent breast-conserving surgery, while the remaining 33 (4.4%) converted to mastectomy. Among the patients who underwent breast-conserving surgery, 112 (15.4%) had an initial positive margin on a frozen margin evaluation, underwent one-time margin re-excision and achieved a margin-free status, while 1.6% underwent a second margin resection due to a positive result on the first re-excised margin. In total, 72.7% of the conversions to mastectomy were due to a positive initial margin. Univariate and multivariate analyses showed that patients with the ductal carcinoma in situ (DCIS) histological type were more likely to have repeatedly positive re-excised margins during breast-conserving surgery. Routine intraoperative frozen margin evaluation of re-excised margins provided only limited value in patients who underwent attempted breast-conserving surgery; this method may be beneficial in the subgroup of patients with the ductal carcinoma in situ histological type.

Automated summary

Intraoperative frozen section analysis of lumpectomy margins can decrease reoperation rates in breast cancer patients undergoing breast-conserving surgery. However, routine intraoperative frozen margin evaluation may have limited value in analyzing re-excised margins in these patients.