Bethesda criteria for microsatellite instability testing: impact on the detection of new cases of Lynch syndrome

2012 ◽  
Vol 11 (4) ◽  
pp. 571-578 ◽  
Author(s):  
Miguel Serrano ◽  
Pedro Lage ◽  
Sara Belga ◽  
Bruno Filipe ◽  
Inês Francisco ◽  
...  
2008 ◽  
Vol 31 (4) ◽  
pp. 12
Author(s):  
A J Hyde ◽  
D Fontaine ◽  
R C Green ◽  
M Simms ◽  
P S Parfrey ◽  
...  

Background: Lynch Syndrome is an autosomal dominant trait that accounts forapproximately 3% of all cases of colorectal cancer (CRC). It is caused by mutations in DNA mismatch repair (MMR) genes, most commonly MLH1 or MSH2. These MMR defects cause high levels of microsatellite instability (MSI-H) in the tumours. MSI testing of all CRCs to identify potential Lynch Syndrome cases is not practical, so the Bethesda Guidelines, which use clinical and pathological features, were created to identify those tumours most likely to be MSI-H^1. In 2007 Jenkins et. al. created MsPath, a tool based on the pathological features described in the rarely used 3^rd Bethesda criterion, to improve prediction of MSI-H tumours among CRC cases diagnosed before age 60 years^2. Methods: We collected a population-based cohort of 716 CRC cases diagnosed before age 75 years in Newfoundland. For each of these cases we collected family history, performed MSI analysis, and scored a number of pathological features for the purpose of evaluating the accuracy of the Bethesda Criteria and MsPath at predicting MSI-H tumours. Results: Our work validates the MsPath tool in the Newfoundland population for the same age group used to create the tool. We found it identified MSI-H cases with a sensitivity of 95% and specificity of 35% in our population of CRCcases diagnosed before age 60 years (n=290). We also tested this tool on our older population of CRCcases, diagnosed at ages 60 to 74 years (n=426). We found it to be at least as predictive in this population,with a sensitivity of 95% and a specificity of 42%. We then used our entire cohort (N=716) to compare MsPath with the other Bethesda criteria.Bethesda criteria 1, 2, 4 and 5 together predicted MSI-H cases with a sensitivity of 67% and a specificity of 51%. MsPath was better at identifying these cases, with a sensitivity of 95% and a specificity of 39%. Conclusions: We conclude that MsPath can be extended to include patients diagnosed with CRC before age 75 years. As well, we have found that MsPath is a better predictive tool than the Revised Bethesda Guidelines for identifying MSI-H cases within a population-based setting of colorectal cancer. References: 1. Umar, A. et. al. J Natl Cancer Inst 2004;96:261-8 2.Jenkins, M.A. et. al. Gastroenterology 2007;133:48-56


2020 ◽  
Vol 21 (2) ◽  
pp. 343-348 ◽  
Author(s):  
Tais Fernanda Marcolino ◽  
Celia Aparecida Marques Pimenta ◽  
Ricardo Artigiani Neto ◽  
Paula Castelo ◽  
Marcelo Souza Silva ◽  
...  

2021 ◽  
pp. jclinpath-2021-207606
Author(s):  
Loëtitia Favre ◽  
Ruiqian Chen ◽  
Yaëlle Bellahsen-Harrar ◽  
Nicolas Ortonne ◽  
Anaïs Pujals

AimSebaceous tumours and keratoacanthomas can be associated with mismatch repair (MMR) deficiency and thus microsatellite instability (MSI). In such tumours, MSI phenotype could be an argument to search for an underlying Muir-Torre syndrome (MTS). MTS has been recognised as a variant of Lynch syndrome, characterised by a deficiency of the MMR proteins. In Lynch syndrome, the sensitivity and specificity of the techniques used to detect MSI is well described, which is not the case for skin tumours. In our hands, immunohistochemistry is a sensitive and specific method to detect MMR deficiency in those tumours. Contrasting with tumours of Lynch spectrum, sensitivity and specificity of molecular methods has not been extensively studied. This study aimed at evaluating two molecular methods to detect MSI phenotype in MTS associated tumours: a commonly used pentaplex PCR using Bethesda markers and the fully automated method using the Idylla MSI assay.MethodsA comparison between PCR, and Idylla was performed on 39 DNA extracted from cutaneous tumours. Immunohistochemistry was used as the gold standard to calculate sensitivity and specificity of both molecular techniques.ResultsConcordant results were found in 32 cases (82%) with pentaplex PCR and in 36 cases (92%) with Idylla. The sensitivity of pentaplex PCR to detect MSI phenotype was 76% whereas Idylla sensitivity was 90%.ConclusionIdylla is more performant than PCR, for the detection of MSI in MTS-associated tumours and is a reliable additional technique to help detecting MTS in these tumours.


2019 ◽  
pp. 1-15
Author(s):  
Karen A. Cadoo ◽  
Diana L. Mandelker ◽  
Semanti Mukherjee ◽  
Carolyn Stewart ◽  
Deborah DeLair ◽  
...  

PURPOSE Mutations in DNA mismatch repair genes and PTEN, diagnostic of Lynch and Cowden syndromes, respectively, represent the only established inherited predisposition genes in endometrial cancer to date. The prevalence of other cancer predisposition genes remains unclear. We determined the prevalence of pathogenic germline variants in unselected patients with endometrial cancer scheduled for surgical consultation. PATIENTS AND METHODS Patients prospectively consented (April 2016 to May 2017) to an institutional review board–approved protocol of tumor-normal sequencing via a custom next-generation sequencing panel—the Memorial Sloan Kettering–Integrated Mutation Profiling of Actionable Cancer Targets—that yielded germline results for more than 75 cancer predisposition genes. Tumors were assessed for microsatellite instability. Per institutional standards, all tumors underwent Lynch syndrome screening via immunohistochemistry (IHC) for mismatch repair proteins. RESULTS Of 156 patients who consented to germline genetic testing, 118 (76%) had stage I disease. In 104 patients (67%), tumors were endometrioid, and 60 (58%) of those tumors were grade 1. Twenty-four pathogenic germline variants were identified in 22 patients (14%): seven (4.5%) had highly penetrant cancer syndromes and 15 (9.6%) had variants in low-penetrance, moderate-penetrance, or recessive genes. Of these, five (21%) were in Lynch syndrome genes (two MSH6, two PMS2, and one MLH1). All five tumors had concordant IHC staining; two (40%) were definitively microsatellite instability–high by next-generation sequencing. One patient had a known BRCA1 mutation, and one had an SMARCA4 deletion. The remaining 17 variants (71%) were incremental findings in low- and moderate-penetrance variants or genes associated with recessive disease. CONCLUSION In unselected patients with predominantly low-risk, early-stage endometrial cancer, germline multigene panel testing identified cancer predisposition gene variants in 14%. This finding may have implications for future cancer screening and risk-reduction recommendations. Universal IHC screening for Lynch syndrome successfully identifies the majority (71%) of high-penetrance germline mutations.


Cancer ◽  
2019 ◽  
Vol 125 (18) ◽  
pp. 3172-3183 ◽  
Author(s):  
Ryan M. Kahn ◽  
Sushmita Gordhandas ◽  
Brandon Paul Maddy ◽  
Becky Baltich Nelson ◽  
Gulce Askin ◽  
...  

2014 ◽  
Vol 207 (10-12) ◽  
pp. 495-502 ◽  
Author(s):  
Eduardo Vilar ◽  
Maureen E. Mork ◽  
Amanda Cuddy ◽  
Ester Borras ◽  
Sarah A. Bannon ◽  
...  

2019 ◽  
Author(s):  
Preethi Srinivasan ◽  
Chaitanya Bandlamudi ◽  
Jinru Shia ◽  
Alicia S. Latham ◽  
Philip Jonsson ◽  
...  

2020 ◽  
Vol 30 (12) ◽  
pp. 1951-1958
Author(s):  
Soyoun Rachel Kim ◽  
Alicia Tone ◽  
Raymond Kim ◽  
Matthew Cesari ◽  
Blaise Clarke ◽  
...  

ObjectivesFor synchronous endometrial and ovarian cancers, most centers rely on mismatch repair testing of the endometrial cancer to identify Lynch syndrome, and neglect the ovarian tumor site completely. We examined the mismatch repair immunohistochemistry and microsatellite instability results from the endometrium and ovary to assess discordance between the tumor sites and between tests.Methods30 women with newly diagnosed synchronous endometrial and ovarian cancer were prospectively recruited from three cancer centers in Ontario, Canada. Both tumor sites were assessed for mismatch repair deficiency by immunohistochemistry and microsatellite instability test; discordance in results between tumor sites and discordance between test results at each site was examined. Cases with discordant results had tumors sequenced with a targeted panel in order to reconcile the findings. All women underwent mismatch repair gene germline testing.ResultsOf 30 patients, 11 (37%) were mismatch repair deficient or microsatellite instable at either tumor site, with 5 (17%) testing positive for Lynch syndrome. Mismatch repair immunohistochemistry expression was discordant between endometrial and ovarian tumor sites in 2 of 27 patients (7%) while microsatellite instability results were discordant in 2 of 25 patients (8%). Relying on immunohistochemistry or microsatellite instability alone on the endometrial tumor would have missed one and three cases of Lynch syndrome, respectively. One patient with Lynch syndrome with a PMS2 pathogenic variant was not detected by either immunohistochemistry or microsatellite instability testing. The rate of discordance between immunohistochemistry and microsatellite instability test was 3.8% in the ovary and 12% in the endometrium.ConclusionsThere was discordance in immunohistochemistry and microsatellite instability results between tumor sites and between tests within each site. Endometrial tumor testing with mismatch repair immunohistochemistry performed well, but missed one case of Lynch syndrome. Given the high incidence of Lynch syndrome (17%), consideration may be given to germline testing in all patients with synchronous endometrial and ovarian cancers.


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