Microsatellite instability testing in colorectal patients with Lynch syndrome: lessons learned from a case report and how to avoid such pitfalls.
Adeleke, Sola Haslam, Aidan Choy, Adrian Diaz-Cano, Salvador Galante, Joao R Mikropoulos, Christos Boussios, Stergios
Adeleke, Sola
Haslam, Aidan
Choy, Adrian
Diaz-Cano, Salvador
Galante, Joao R
Mikropoulos, Christos
Boussios, Stergios
Abstract
We present the case of a patient with Lynch syndrome and metastatic colorectal carcinoma (mCRC). The initial immunohistochemistry (IHC) test for deficient mismatch repair gave a false negative result. However, the same mutation has accurately been detected with IHC in other cancers with microsatellite instability (MSI). This supports the determining role of somatic missense mutations in MMR IHC. MSI-PCR testing confirmed MSI and the patient benefited from nivolumab with a complete metabolic response. We explain the rationale for immunotherapy in mCRC, current testing strategies and discuss future developments in MSI testing. We advocate for upfront testing using both IHC and MSI-PCR to direct therapy in mCRC, and a greater understanding of IHC and MSI-PCR testing pitfalls.
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Date
2022-06-16
Type
Article
Subject
Neurology, Oncology. Pathology., Pharmacology
Collections
Citation
Adeleke S, Haslam A, Choy A, Diaz-Cano S, Galante JR, Mikropoulos C, Boussios S. Microsatellite instability testing in colorectal patients with Lynch syndrome: lessons learned from a case report and how to avoid such pitfalls. Per Med. 2022 Jul;19(4):277-286. doi: 10.2217/pme-2021-0128. Epub 2022 Jun 16
Journal / Source Title
Personalized Medicine
DOI
10.2217/pme-2021-0128
PMID
35708161
Publisher
Taylor and Francis Group
Publisher’s URL
http://www.futuremedicine.com/loi/pme