[212] Comparison of Margin Status of Separate Cavity Margins and Lumpectomy Margins in Breast Conserving Surgery

Yanxia Li, Ian Hughes, Reeba Omman, Woodlyne Roquiz, Xiuzhen Duan, Anna Szpaderska, Claudia Perez, Constantine Godellas, Cagatay Ersahin. Loyola University Medical Center, Maywood, IL

Background: The surgical margin status of breast-conserving surgery (BCS) predicts local recurrence and determined the need for re-excision. Two widely used methods to evaluate the margins have been applied in BCS, the lumpectomy margins (LM) vs. separate cavity margins (CM) as final margins (FM). Studies comparing the two types of BCSs are limited, and differences between them are not well defined, but a few studies have shown that taking additional CMs reduces the need for re-excision.
Design: In our study, a positive margin is defined as the tumor located less than 1 mm to the inked margin for both LM and CM. In cases with CM, 4 to 6 separate margins are evaluated as FM. The margin status of 582 patients who underwent BCS in our institution from 2005 to 2011 has been evaluated including 420 CM and 162 LM cases. The tumors identified in the specimens are divided into 3 categories, invasive cancer (InvCa) only, carcinoma in-situ (CIS) only and both (Inv&CIS). If one or more FMs are positive, it is counted as a case with a positive margin. The percentages of the cases with positive FMs are compared in each tumor category between LM and CM specimen.
Results: In InvCa, CIS, and Inv&CIS categories, there are 30, 57, and 75 LM cases, respectively; and 69, 96, and 225 CM cases, respectively. Figure 1 compares the %positive-cases in LM and CM devided into 3 tumor groups.

In all tumor groups, CM shows a statistically lower FM positivity rate than LM does (*p < 0.05), with 58%, 24%, and 50% reduction comparing to LM, in InvCa, CIS, and Inv&CIS, respectively. Interestingly, in both LM and CM cases, CIS tumor groups show highest positivity rate, whereas InvCa tumors reveal the lowest positivity rate among all tumor groups.
Conclusions: Our study demonstrates that taking separate CM in BCS render a better and cleaner overall FM status compared to taking LMs, therefore reducing the need of re-excision. InvCa is more likely to be completely excised than CIS by both LM and CM methods. Future studies will evaluate other potential predictors of margin status (e.g. tumor size, grade, lymph node status etc.), and corelate the local recurrence and survival data to define the role of LM and CM in patient management.
Category: Breast

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 28, Monday Morning

 

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