[1053] Algorithmic Approach to Intraoperative Consultation/Frozen Section May Reduce Discrepancies and Surgical Understaging in Differrent Types of Endometrial Cancer

A Cabrera, M Cibull, F Ueland, C DeSimone, RG Karabakhtsian. University of Kentucky, Lexington, KY

Background: Intraoperative consultation (IOC) with frozen section (FS) for endometrial cancer (EC) is an important management tool for subtyping, staging and treatment. However, studies have shown discrepancies between tumor type and stage at FS and final diagnosis (FDx), mostly involving high-grade (HG) EC, including HG endometrioid (EMC), and most importantly, serous (SC) and clear cell (CCC). These so-called “type 2” EC often show atypical growth pattern, which may result in underestimated depth of myometrial invasion (DMI) and understaging at IOC. Since the management for deeply invasive “type 2” tumors is the same as that for superficially invasive ones (due to high likelihood of early extrauterine spread), a legitimate question arises regarding the need to evaluate those for DMI at IOC.
Design: Pathology reports of 89 hysterectomies for EC at UK from 1/09 through 8/09 yielded 71 EMC (62 FIGO G1/2 and 9 G3), 6 SC, 5 CCC, 7 mixed. An algorithmic approach was attempted at IOC, partly on the basis of known diagnoses on prior biopsies, and partly based on gross evidence of advanced disease. Known FIGO G1/2 EMC were to be evaluated by FS for DMI and HG EC only for presence of myometrial invasion (MI). High-stage tumors as evidenced by gross adnexal, cervical, or serosal involvement, were to be excluded from FS. The diagnoses/stage at IOC/FS were compared to those at FDx.
Results: Of 62 FIGO G1/2 EMC, FS was performed in 81% (50/62). Of those only 4% (2/50) had discrepancies in DMI. Of 27 HG tumors FS was performed in 52% (14/27) and withheld in 48% (13/27). In 14% (2/14) of HG EC the final pathologic staging was discrepant from that at FS regarding the DMI. A total of 21 tumors were of high-stage, including 7 LG and 14 HG. Of the 21 high-stage tumors, FS was performed in 48% (10/21) with one discrepant case, and withheld in 52% (11/21).
Conclusions: 1) FS for EC may be avoided when gross evidence of advanced disease is present, regardless of tumor type or grade. 2) In HG EC, FS may be performed to determine only the absence (pelvic node sampling only) or presence (also paraaortic node sampling) of MI to minimize the potential for diagnostic underestimation and surgical understaging. 3) FS for DMI may be reserved for FIGO G1/2 EMC only. 4) Although the discrepancy rate between FS and FDx is higher for HG (14%) compared to LG (2%) EC, an algorithmic approach appears to lower the overall rate of discrepancy compared to those reported in the literature (up to 30%).
Category: Gynecologic & Obstetrics

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 138, Wednesday Morning

 

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