Margin Assessment in Breast Conservation for Ductal Carcinoma In Situ.

Abstract

IntroductionBreast conserving surgery in the setting of ductal carcinoma in situ (DCIS) produces many challenges. Re-excision rates for close or negative margins after lumpectomy are common due to difficulty in intraoperative margin status assessment. The objective of this study was to review our experience with various margin assessment techniques in the setting of a preoperative diagnosis of DCIS on core needle biopsy (CNB).MethodsA prospectively gathered database of surgically-treated breast cancer patients was reviewed for patients with a diagnosis of DCIS as the most significant lesion on CNB from 1997 to 2009. Of 425 patients with a diagnosis of DCIS by CNB, 231 patients underwent a lumpectomy. Patients' age, tumor characteristics, type of surgery, margin assessment technique, and follow up data were recorded.Results231 patients underwent a lumpectomy following a CNB of DCIS. 138 patients (59.7%) had intra-operative touch prep (TP) analysis of all 6 margins, 39 patients (16.9%) underwent intra-operative gross evaluation of margins, 53 (22.9%) patients had no intra-operative analysis, and one patient (0.4%) had a frozen section analysis. Success at achieving negative margins (>2mm) with initial lumpectomy was 66.7% (92/138) for TP analysis, 56.4% (22/39) for gross evaluation, and 52.8% (28/53) for no margin assessment. These percentages did not reach statistical significance by odds ratios (TP to Gross p= 0.24, TP to None p=0.08, Gross to None p=0.73). After excluding patients that required mastectomy following an unsuccessful lumpectomy, ipsilateral breast recurrence rates were 6.3% (8/127) for the touch prep patients after a mean follow up of 4.0 years, 0.0% (0/31) for the gross evaluation patients after a mean follow up of 1.9 years, and 10.5% (4/38) for the patients with no intraoperative assessment after a mean follow up of 3.8 years. Characteristics of each group are listed in Table 1.ConclusionsReexcision for close or positive margins is required for a significant percentage of patients who undergo lumpectomy after a preoperative diagnosis of DCIS on CNB. Although intraoperative TP analysis had the highest success of preventing reexcision, long term data suggest that recurrence rates between intraoperative TP and gross evaluation are both acceptable with short term follow up.Table 1: Characteristics of patients undergoing lumpectomy with a preoperative diagnosis of DCIS on CNBMargin AssessmentTouch PrepGrossNoneFrozenNumber of cases13839531Patient Median Age59.758.956.359.8Cases not needing Reexcision66.7%(92/138)56.4% (22/39)52.8% (28/53)0%(0/1)Cases that received mastectomy8.0%(11/138)20.5%(8/39)26.4%(14/53)100%(1/1)DCIS Grade3- 512- 631- 22Unk- 23- 162- 151- 5Unk- 33-252-201- 7Unk- 13- 02- 01- 1Unk- 0Cases with Necrosis50%(69/138)53.9%(21/39)62.3%(33/53)0%(0/1)Cases upgraded to Invasive Cancer12.3%(17/138)15.4%(6/39)35.9%(19/53)0%(0/1)ReceivedRadiation after lumpectomy85.0%(108/127)67.7% (21/31)76.3%(29/38)0%(0/1)ReceivedTamoxifen after lumpectomy34.7%(44/127)25.8%(8/31)31.2%(12/38)0%(0/1)Ipsilateral breastRecurrence after lumpectomy6.3%(8/127)0%(0/31)10.5% (4/38)0%(0/1)Follow up after lumpectomy (years)4.0(0-10.6)1.9(0.19-5.6)3.8(0.17-9.4)6.0 Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4122.