Intra-Operative Margin Evaluation of Breast Specimens: Value of Gross Evaluation
Abbie R Mallon, David J Dabbs, Ronald R Johnson, Gretchen M Ahrendt, Kandace P McGuire, Marguerite Bonaventura, Rohit Bhargava. Magee-Womens Hospital of UPMC, Pittsburgh, PA
Background: Intra-operative frozen section (FS) analysis of breast tissue is generally not recommended as it is difficult to freeze adipose tissue which results in sub-optimal sections and has the potential for erroneous diagnosis. Contrary to the general belief, a recent study (Jorns et al. Mod Pathol 2011;24(supp 1):46A-Abstract 183) suggests that the benefits of intraoperative FS for margin evaluation are under-estimated (study showed reduction in re-excision rate from 55.3% without FS to 19.4% with FS). However, the study did not evaluate if gross intra-operative evaluation would provide the same information.
Design: A retrospective evaluation of all breast segmental resections for invasive carcinoma for the calendar year 2010 was performed. All surgeries were performed by breast surgeons with median experience of >10 years. Whether an intra-operative gross evaluation was requested by the surgeon was recorded. FS for margin evaluation on breast specimens are not performed at our institution. Several factors are considered by surgeons for re-excision, that not only includes margin width (i.e. < 2mm) but also tumor histology, co-morbidities, margin type, extent of involvement and cosmetic outcome. The number of patients that underwent second surgery for margins was used to define the re-excision rate.
Results: A total of 365 invasive carcinomas were identified. Intra-operative gross evaluation was requested on 58 (16%) invasive carcinomas. The cases where intra-operative gross evaluation was not requested (i.e. 307 cases), surgeons themselves performed small re-excisions at the time of initial surgery if they felt "clinically close" (either by palpation or specimen radiograph) to the lesion in 94 (31%) cases. The re-excision rate (i.e. second surgery) for invasive carcinomas without gross intra-operative evaluation was 19% (58 of 307) and with gross intra-operative evaluation was 7% (4 of 58). This difference in re-excision rate between the 2 groups was statistically significant (p=0.02).
Conclusions: The re-excision rate at our institution is at the lower end of the spectrum likely due to the high volume and sub-specialty nature of the practice. However, gross intra-operative evaluation of the thinly sliced breast specimen further reduces the re-excision rate for positive or close margins. There is no need for frozen section analyses as the benefits derived will be minimal and will result in sub-optimal evaluation of margins on permanent sections.
Monday, March 19, 2012 1:00 PM
Poster Session II # 79, Monday Afternoon