Universal screening of colorectal cancers (CRCs) is recommended to increase the diagnosis of Lynch syndrome. Tumor screening can be done by microsatellite instability (MSI) testing, but immunohistochemistry (IHC) staining on the tumor is less expensive, easier, and more available. <\/p>\n\n\n\n
This study is a literature review of IHC testing and its outcomes. Among 58,580 unselected CRCs included, about 10% showed mismatch repair deficiency (MMRd) on IHC, and about half of these resulted from hypermethylation of MLH1<\/em>. Hypermethylation assays were more effective at identifying epigenetic inactivation of MLH1<\/em> compared to BRAF<\/em> mutation analysis. About 6% of all CRCs warranted genetic testing, and an MMR germline variant was found in 38%, corresponding to 2% of all CRCs, 33% of all MMRd CRCs, and increasing to 7.3% of all CRCs in patients younger than age 50 years and 5.0% of patients under 70 years. <\/p>\n\n\n\n Across all studies, approximately 4% of all CRCs had unexplained MMRd, but when a detailed gene analysis was performed, the rate of unexplained MMRd dropped to 0.61%, with biallelic somatic MMR inactivation as the most common explanation.<\/p>\n","protected":false},"excerpt":{"rendered":" Universal screening of colorectal cancers (CRCs) is recommended to increase the diagnosis of Lynch syndrome. Tumor screening can be done by microsatellite instability (MSI) testing, but immunohistochemistry (IHC) staining on the tumor is less expensive, easier, and more available. This study is a literature review of IHC testing and its outcomes. Among 58,580 unselected CRCs … Read more<\/a><\/p>\n","protected":false},"template":"","categories":[1768,1769],"tags":[2058,2059,2741,2742,2740],"class_list":["post-10413","ec-news","type-ec-news","status-publish","hentry","category-asge-journal-scan","category-asge-kolon","tag-colon-2","tag-ihc","tag-mismatch-repair-deficiency","tag-mmrd","tag-pathology-reports-of-crcs"],"_links":{"self":[{"href":"https:\/\/www.endoscopy-campus.com\/en\/wp-json\/wp\/v2\/ec-news\/10413","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.endoscopy-campus.com\/en\/wp-json\/wp\/v2\/ec-news"}],"about":[{"href":"https:\/\/www.endoscopy-campus.com\/en\/wp-json\/wp\/v2\/types\/ec-news"}],"wp:attachment":[{"href":"https:\/\/www.endoscopy-campus.com\/en\/wp-json\/wp\/v2\/media?parent=10413"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.endoscopy-campus.com\/en\/wp-json\/wp\/v2\/categories?post=10413"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.endoscopy-campus.com\/en\/wp-json\/wp\/v2\/tags?post=10413"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}