1.Clinical Pathology Division, Translational Research Unit, Institute of Pathology, University of Bern, Murtenstrasse 31, CH-3010 Bern, Switzerland2.Department of Molecular Biology, Genetics, Middle East Technical University, Ankara 06531 Turkey (NS); Department of Biological Sciences, Middle East Technical University, Ankara 06531, Turkey (SB)3.Clinical Pathology Division, Translational Research Unit, Institute of Pathology, University of Bern, Murtenstrasse 31, CH-3010 Bern, Switzerland4.INSERM U434, Laboratoire de Genetique des Tumeurs, CEPH, Paris
Molecular pathway- Chromosome instability (CIN)-- 85% of all CRCs-- Somatic inactivation of APC, p53;- Microsatellite instability (MSI)-- 15% of all CRCs-- Hypermethylation or somatic inactivation of DNA repair enzymes;
Etiology- Sporadic CRC-- 84% microsatellite stable (MSS) CRC-- 10% microsatellite instable (MSI) CRC;- Hereditary CRC-- 1% Familial Adenomatous Polyposis (FAP) (MSS CRC)-- 5% Hereditary Non-Polyposis Colorectal Cancer (HNPCC) (MSI CRC).
In the last years, downstream molecules of different pathways such as KRAS and BRAF are included in proposals for a more differentiated molecular classification of CRC.The CpG Methylator Phenotype (CIMP) status also seems to play an important role in the pathogenesis of CRC.
The different histological subtypes include:- Adenocarcinoma-- Mucinous adenocarcinoma-- Signet ring cell carcinoma-- Medullary carcinoma-- Serrated adenocarcinoma-- Cribriform comedo-type adenocarcinoma-- Micropapillary adenocarcinoma- Adenosquamous carcinoma- Spindle cell carcinoma- Squamous cell carcinoma- Undifferentiated carcinoma.
The gold standard for staging is the TNM classification proposed by the UICC/AJCC.Important parameters included in the TNM classification are:- T : Primary Tumor- N: Regional Lymph Nodes- M: Distant Metastasis- G: Histopathological grading- L: Lymphatic invasion- V: Venous invasion- Pn: Perineural invasion.
Molecular features in Pathology that can be important in the daily diagnostic practice are:- Microsatellite status: Determined by immunohistochemistry and/or PCR- KRAS status: Determined by PCR- BRAF status: Determined by PCR.
Viktor H Koelzer ; Heather Dawson ; Inti Zlobec ; Alessandro Lugli
Colon: Colorectal adenocarcinoma
Atlas Genet Cytogenet Oncol Haematol. 2012-12-01
Online version: http://atlasgeneticsoncology.org/solid-tumor/5006/colonid5006
2007-05-01 Colon: Colorectal adenocarcinoma by Nilufer Sayar,Sreeparna Banerjee
1998-04-01 Colon: Colorectal adenocarcinoma by Richard Hamelin