title: [Molecular pathology of colorectal cancer].
abstract: In recent years, several predictive and prognostic biomarkers have been established in colorectal cancer (CRC). The RAS-mutation status is widely applied in the daily routine diagnostic as predictive biomarker for treatment with EGFR-inhibitors. A BRAF- mutation has no predictive value in this context. The detection of high-grade microsatellite instability (MSI-H) is a predictive biomarker for response to 5-Fluoruracil-monotherapy. Prognostic biomarkers in CRC are the MSI-status and the mutational status of BRAF. According to the current WHO classification poorly and undifferentiated CRC and MSI-associated special morphological subtypes are molecular graded depending on their MSI-status. The detection of a BRAF-mutation in the context of microsatellite stability (MSS) is associated with a very poor prognosis and thus represents the most aggressive molecular subtype of CRC. In patients with positive Bethesda criteria a stepwise immunohistochemical and molecular diagnostic scheme is proposed.
authors.affiliation: Pathologisches Institut, Ludwig-Maximilians-Universität München, Thalkirchner Straße 36, 80337, München, Deutschland, jens.neumann@med.uni-muenchen.de.
authors.forename: J H L
authors.initials: JH
authors.lastname: Neumann
authors.forename: A
authors.initials: A
authors.lastname: Jung
authors.forename: T
authors.initials: T
authors.lastname: Kirchner
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology; D000465:Algorithms; D058534:Class I Phosphatidylinositol 3-Kinases; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics / Q000473:pathology; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D005472:Fluorouracil / Q000627:therapeutic use; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D053842:Microsatellite Instability; D025202:Molecular Diagnostic Techniques; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics
chemical_list: D005819:Genetic Markers; D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; C512478:EGFR protein, human; D066246:ErbB Receptors; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D005472:Fluorouracil