Colorectal cancer: Update

Colorectal cancer is considered to be the fourth most common cause of cancer deaths all over the world.Colorectal Carcinoma (CRC) exhibits wide geographical variations in frequency. It is more common in industrialized countries. There are number of risk factors that contribute to the development of colorectalcarcinoma including genetic risk factors, adenomas and hyperplastic polyps, idiopathic inflammatory bowel disease and others.About 25% of patients of CRC have a family history that suggests a genetic attribution, common exposures among family members or a combination of both. Some genetic syndromes include:- Familial Adenomatous Polyposis (FAP), most commonly caused by mutation of APC gene.- Attenuated FAP, also caused by mutation of APC gene.- Hereditary Non-Polyposis Colorectal Cancer (HNPCC), caused by mutations of DNA Mismatch Repair genes (MMR).- Peutz-Jephers Syndrome (PJS), caused by mutation OfSTK11 gene.- Juvenile Polyposis Syndrome (JPS), caused by mutation of MADH4 gene or Bone Morphogenic Protein Receptor IA (BrvtPR, A).- Hereditary mixed polyposis, caused by mutation at locus 15qI3-qI4.- Hereditary breast and colon cancer, caused by mutation of CHEKz.Adenomatous and carcinomatous transformation in hyperplastic polyps have been reported, a feature usually associated with large polyp size or with patients having multiple polyps with no family history.Neoplastic changes in hyperplastic polyposis eases may be driven by ”’#” DNA microsatellite instability.