Utility of immunohistochemistry for mismatch repair proteins on colorectal polyps in the familial cancer clinic

Dow, Eryn; Buchanan, Daniel D.; Winship, Ingrid

doi:10.1111/imj.13953

Cited by 2 publications

(1 citation statement)

References 17 publications

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“…In agreement, an independent study found that 3.2% (4/125) of advanced adenomas from patients aged <50 years were MMR deficient, leading to an LS diagnosis in 2.4% (3/125) of the cohort [246]. Similarly, 5.3% (3/57) of colorectal adenomas from familial cancer clinic patients were MMR deficient, and germline MMR gene testing of these patients showed that 3.5% (2/57) of the cohort had LS [247]. These yields of LS diagnoses from molecular screening of selected colorectal adenomas are equivalent to universal molecular screening of CRCs, suggesting that young or high-risk patients with colorectal adenomas could be screened for LS following current guidance for CRCs.…”

Section: Msi Analysis Of Cns Tumours Has a Low Sensitivity For Mmr Deficiencymentioning

confidence: 98%

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

Gallon

Gawthorpe

Phelps

et al. 2021

Cancers

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International guidelines for the diagnosis of Lynch syndrome (LS) recommend molecular screening of colorectal cancers (CRCs) to identify patients for germline mismatch repair (MMR) gene testing. As our understanding of the LS phenotype and diagnostic technologies have advanced, there is a need to review these guidelines and new screening opportunities. We discuss the barriers to implementation of current guidelines, as well as guideline limitations, and highlight new technologies and knowledge that may address these. We also discuss alternative screening strategies to increase the rate of LS diagnoses. In particular, the focus of current guidance on CRCs means that approximately half of Lynch-spectrum tumours occurring in unknown male LS carriers, and only one-third in female LS carriers, will trigger testing for LS. There is increasing pressure to expand guidelines to include molecular screening of endometrial cancers, the most frequent cancer in female LS carriers. Furthermore, we collate the evidence to support MMR deficiency testing of other Lynch-spectrum tumours to screen for LS. However, a reliance on tumour tissue limits preoperative testing and, therefore, diagnosis prior to malignancy. The recent successes of functional assays to detect microsatellite instability or MMR deficiency in non-neoplastic tissues suggest that future diagnostic pipelines could become independent of tumour tissue.

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Section: Msi Analysis Of Cns Tumours Has a Low Sensitivity For Mmr Deficiencymentioning

confidence: 98%

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

Gallon

Gawthorpe

Phelps

et al. 2021

Cancers

View full text Add to dashboard Cite

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Single-center study of Lynch syndrome screening in colorectal polyps

Zhu

Pan

Zhang

et al. 2019

Hered Cancer Clin Pract

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BackgroundLynch syndrome is the most common hereditary colorectal cancer syndrome, and adenoma is one of the important premalignant lesions to colorectal cancer in Lynch syndrome. The first objective of this study was to calculate the detection rate of Lynch syndrome in colorectal polyps by using mismatch repair immunohistochemistry as the initial screening strategy. The second objective of this study was to optimize screening strategies for adenoma associated with Lynch syndrome by integrating polyp and/or patient characteristics such as polyp size, location, dysplasia, age of onset and/or family history of cancer.MethodsFrom June 2014 to May 2016, immunohistochemistry was performed for mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) using endoscopically resected specimens obtained from newly diagnosed colorectal adenomas. Gene analysis was performed in patients with missing expression of mismatched repair protein.ResultsFive hundred and ten patients underwent colorectal polyp resection, with a total of 718 polyps. Five hundred and eight resected adenomas underwent mismatch repair protein immunohistochemical testing. Loss of mismatch repair protein expression was observed in six adenomas, accounting for 1.18% of all adenomas. Five patients then underwent genetic tests to identify two pathogenic mutations from different individuals, while another patient was suspected to have a pathogenic mutation. Three patients were younger than 50 years old. Two patients had advanced histology (high-grade dysplasia and malignant components) and one patient had a family history of cancer.ConclusionImmunohistochemical detection of colorectal polyp mismatch repair protein as Lynch syndrome screening efficiency is low. Effective screening strategies may be improved by optimizing patient/polyp selection, such as focusing on young adenoma patients with a family history of cancer, or patients who present with high-risk features (large size, villous, high-grade dysplasia and malignant components).

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Utility of immunohistochemistry for mismatch repair proteins on colorectal polyps in the familial cancer clinic

Cited by 2 publications

References 17 publications

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

Single-center study of Lynch syndrome screening in colorectal polyps

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