TY - JOUR
T1 - Performance of immunohistochemical and molecular methods in detecting microsatellite instability in gastric cancer
T2 - a multicenter study
AU - Marques, Diogo Sousa
AU - Gullo, Irene
AU - Mascarenhas-Lemos, Luís
AU - Silva, João Ricardo
AU - Nascimento, Catarina Neto do
AU - Pontes, Patricia
AU - Pinho, Lidia
AU - Cirnes, Luis
AU - Wen, Xiaogang
AU - Cravo, Marilia
AU - Carneiro, Fátima
N1 - Publisher Copyright:
© 2023 S. Karger AG, Basel. Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
PY - 2023/12/1
Y1 - 2023/12/1
N2 - Introduction: Introduction: Microsatellite instability (MSI) is an important prognostic molecular biomarker for gastric cancer (GC). MSI status may be detected by immunohistochemistry (IHC) for mismatch repair (MMR) proteins and polymerase chain reaction (PCR). Idylla MSI assay has not been validated for GC but may prove to be a valid alternative.Methods: In a series of 140 GC cases, MSI status was evaluated by IHC for MLH1, PMS2, MSH2, and MSH6; gold-standard pentaplex PCR panel (PPP) (BAT-25, BAT-26, NR-21, NR-24, and NR-27); and Idylla. Statistical analysis was performed using SPSS 27.0.Results: PPP identified 102 microsatellite stable (MSS) cases and 38 MSI-high cases. Only three cases showed discordant results. Compared with PPP, the sensitivity was 100% for IHC and 94.7% for Idylla. Specificity was 99% for IHC and 100% for Idylla. MLH1 IHC alone showed sensitivity and specificity of 97.4% and 98.0%, respectively. IHC identified three indeterminate cases; all were MSS according to PPP and Idylla.Conclusion: IHC for MMR proteins represents an optimal screening tool for MSI status in GC. If resources are limited, isolated MLH1 evaluation may constitute a valuable option for preliminary screening. Idylla may help detect rare MSS cases with MMR-loss and define MSI status in indeterminate cases.
AB - Introduction: Introduction: Microsatellite instability (MSI) is an important prognostic molecular biomarker for gastric cancer (GC). MSI status may be detected by immunohistochemistry (IHC) for mismatch repair (MMR) proteins and polymerase chain reaction (PCR). Idylla MSI assay has not been validated for GC but may prove to be a valid alternative.Methods: In a series of 140 GC cases, MSI status was evaluated by IHC for MLH1, PMS2, MSH2, and MSH6; gold-standard pentaplex PCR panel (PPP) (BAT-25, BAT-26, NR-21, NR-24, and NR-27); and Idylla. Statistical analysis was performed using SPSS 27.0.Results: PPP identified 102 microsatellite stable (MSS) cases and 38 MSI-high cases. Only three cases showed discordant results. Compared with PPP, the sensitivity was 100% for IHC and 94.7% for Idylla. Specificity was 99% for IHC and 100% for Idylla. MLH1 IHC alone showed sensitivity and specificity of 97.4% and 98.0%, respectively. IHC identified three indeterminate cases; all were MSS according to PPP and Idylla.Conclusion: IHC for MMR proteins represents an optimal screening tool for MSI status in GC. If resources are limited, isolated MLH1 evaluation may constitute a valuable option for preliminary screening. Idylla may help detect rare MSS cases with MMR-loss and define MSI status in indeterminate cases.
KW - Diagnostic accuracy
KW - Gastric cancer
KW - Idylla
KW - Immunohistochemistry
KW - Microsatellite instability
KW - Mismatch-repair proteins
KW - Multiplex polymerase chain reaction
UR - http://www.scopus.com/inward/record.url?scp=85170842156&partnerID=8YFLogxK
U2 - 10.1159/000530997
DO - 10.1159/000530997
M3 - Article
C2 - 37271124
SN - 1015-2008
VL - 90
SP - 389
EP - 399
JO - Pathobiology
JF - Pathobiology
IS - 6
ER -
