Intraoperative margin assessment reduces reexcision rates in patients with ductal carcinoma in situ treated with breast-conserving surgery

Background Reported rates of reexcision for margin control after breast-conserving surgery for ductal carcinoma in situ (DCIS) range from 48% to 59%. The optimal technique for intraoperative margin assessment in patients with DCIS has yet to be defined. We sought to determine whether intraoperative multidisciplinary evaluation using gross tissue assessment and sectioned-specimen radiography reduces the need for reoperation for margin control in DCIS. Methods A prospectively compiled database was used to identify patients who had DCIS diagnosed by core needle biopsy and were treated with breast-conserving surgery at our institution between July 1999 and July 2002. All patients had intraoperative gross margin assessment and specimen radiography of both the whole and sliced specimen for calcifications. Results Four hundred two patients with DCIS were evaluated at our institution during the study period. Of these, 160 had excisional biopsy for diagnosis prior to referral, 92 had mastectomy as their initial procedure, 40 were seen for a second opinion only, and 1 patient refused surgery. The remaining 109 patients formed the study population. The median age was 55 years (range 34 to 81). The median pathologic size of DCIS was 1.2 cm (range 0.2 to 8.0 cm). Fifty-nine patients had positive (less than 1 mm) or close (less than 5 mm) margins on intraoperative assessment. Final pathology agreed with intraoperative assessment of a positive or close margin in 43 of the 59 patients (P = 0.00005). Seventy-five percent of those thought to have a positive or close margin at the time of surgery (n = 44) underwent intraoperative reexcision. Of the total 109 patients, 31 (34%) had an intraoperative reexcision that resulted in a change in margin status from positive on intraoperative evaluation to negative on final pathologic evaluation (P < 0.00001). A second procedure for margin control was necessary in only 24 patients (22%). The decision to excise additional tissue at the first surgery on the basis of intraoperative assessment resulted in significantly fewer second procedures for margin control (P = 0.029). Conclusions In patients with DCIS, intraoperative margin assessment by gross pathological examination and sliced specimen radiography significantly affects intraoperative decision making, and excision of further tissue on the basis of intraoperative assessment results in a substantial decrease in second procedures for margin control.