ACP Analytical Cellular Pathology 2210-7177 2210-7185 IOS Press 430389 10.3233/ACP-CLO-2010-0550 High Frequency Microsatellite Instability Has a Prognostic Value in Endometrial Endometrioid Adenocarcinoma, But Only in FIGO Stage 1 Cases Steinbakk Anita 1, 2, 3 Malpica Anais 4 Slewa Aida 1 Gudlaugsson Einar 1, 3 Janssen Emiel A. M. 1 Arends Mark 5 Kruse Arnold Jan 6 Yinhua Yu 7 Feng Weiwei 8 Baak Jan P. jpabaak@yahoo.com 1, 3 Department of Pathology Stavanger University Hospital Stavanger Norway Department of Gynaecology Stavanger University Hospital Stavanger Norway The Gade Institute University of Bergen Bergen Norway uib.no Departments of Pathology and Gynecologic Oncology The University of Texas MD Anderson Cancer Center Houston TX USA Department of Pathology Addenbrooke’s Hospital University of Cambridge Cambridge England cam.ac.uk Department of Gynecology Academic Medical Center Maastricht The Netherlands Department of Experimental Medicine The University of Texas MD Anderson Cancer Center Houston TX USA Department of Gynecology Obstetrics and Gynecology Hospital of Fudan University Shanghai China 2010 33 5-6 245 255 2010 Copyright © 2010 Hindawi Publishing Corporation and the authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Objectives: To analyze the prognostic value of microsatellite instability (MSI) in a population-based study of FIGO stage 1–4 endometrial endometrioid adenocarcinomas.

Study Design: Survival analysis in 273 patients of MSI status and clinico-pathologic features. Using a highly sensitive pentaplex polymerase chain reaction to establish MSI status, cases were divided into microsatellite stable (MSS), MSI-low (MSI-L, 1 marker positive) and MSI-high (MSI-H, 2–5 markers positive).

Results: After 61 months median follow-up (1-209), 34 (12.5%) of the patients developed metastases but only 6.4% of the FIGO 1. MSI (especially as MSI-H vs. MSS/MSI-Lcombined) was prognostic in FIGO 1 but not in FIGO 2–4. The 5 and 10 year recurrence-free survival rates were 98% and 95% in the MSS/MSI-L vs. 85% and 73% in the MSI-H patients (p=0.005).

Conclusions: MSI-H status assessed by pentaplex polymerase chain reaction is an indicator of poor prognosis in FIGO 1, but not in FIGO 2–4 endometrial endometrioid adenocarcinomas.

 Endometrial cancer endometrioid FIGO stage 1 MSI prognosis