Effect of Not Bisecting Mastectomy and Lumpectomy Specimens Received from Remote Sites on ER/PR Results
Monna Marolt, Sherif Tawfic. Fairview University Medical Center, Minneapolis, MN
Background: The 2010 ASCO/CAP guideline recommendations for ER/PR testing include bisecting lumpectomy/mastectomy specimens through the tumor at remote sites prior to fixation. This has become a CAP requirement in 2011. Appropriate evaluation of surgical margins is also critical for management. The purpose of this study is to determine if not bisecting the specimen affects the percentage of tumor cells staining for ER/PR and/or the intensity of staining.
Design: Lumpectomy/mastectomy specimens with no previous documented biopsy or with negative ER/PR on the diagnostic biopsy were omitted from the study. Twenty specimens received from remote sites in 2010 met the criteria. All cases were not bisected prior to fixation and transport. The following data were collected: specimen size, tumor type and size, distance from margins, cold ischemia time, time until grossing and total fixation time. IHC for ER/PR was performed and interpreted blindly by two pathologists. The results were compared with those obtained on the prior needle core biopsies. HER2 amplification by FISH was performed as applicable.
Results: The study included 2 mastectomy and 18 lumpectomy specimens. The range of specimen and tumor size was 4.0-19.0 cm (mean 8.5 cm) and 0.45-8.0 cm (mean 2.0 cm), respectively. Three cases had a positive margin; otherwise the distance to the closest margin ranged from 0.1 to 2.0 cm (mean 0.4 cm). Three cases were ductal carcinoma in-situ; the rest were invasive carcinoma. The cold ischemia time was less than 1 hr. The fixation time until grossing ranged from 4 to 24 hrs in 19 cases (mean 18 hrs), and 66 hrs in one case. The total fixation time ranged from 6 to 72 hrs. The percentage and the intensity of ER/PR positive tumor cells in the excisional specimens matched those reported for the previous diagnostic biopsies in all cases. ER and PR positivity ranged from 75 to 100% and 0% to 100%, respectively with moderate to strong staining. The two cases with HER2 amplification by FISH on the diagnostic biopsies also showed amplification on the lumpectomy specimens.
Conclusions: There was no difference in percentage of tumor cells staining for ER and PR or staining intensity (as compared to the diagnostic biopsies) when lumpectomy and mastectomy specimens were not bisected at the remote sites. This was noted irrespective of specimen size, tumor size and distance from margin. The tumors in our series had relatively high ER/PR expression with moderate to strong staining, and a larger study with more variable ER/PR expression may be needed.
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 31, Wednesday Afternoon