Hereditary Colorectal Cancer and Lynch Syndrome

Overview

• Colorectal cancer (CRC) is the third most common tumour in men and the second in women, accounting for 10% of all tumour types worldwide. The CRC incidence is 40 per 100,000 persons, most cases of CRC are sporadic, but familial cancer syndromes are also common in this disease.
• Approximately 10% of all cases of CRCs are believed to be hereditary, and up to 30% are thought to have a f. amilial component, including genetic background and common environmental risk factors. Lynch syndrome (LS), previously known as hereditary nonpolyposis colorectal cancer (HNPCC), is the most common hereditary CRC syndrome Most hereditary cancers are associated with a “germline mutation” that will be present in every cell of the human body.
• Identification of patients at risk of inherited cancer susceptibility is dependent upon the ability to characterize genes and alterations associated with increased cancer risk as well as gathering a detailed personal and family history aiding in the identification of the mode of inheritance as well as other family members at risk of suffering from this susceptibility. Most hereditary cancer syndromes follow an autosomal dominant inheritance, and the penetrance is high.

Indication

The Igenomix Hereditary Colorectal Cancer Panel is indicated as a screening and diagnostic test in those cases where there is: 

• Family history of colorectal cancer (CRC) or suspected hereditary colorectal cancer syndrome, such as familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary non-polyposis colon cancer or HNPCC). 
• Family or personal history of Lynch syndrome or Lynch-like syndrome. 
• History of multiple colorectal adenomas. 
• Asymptomatic patient who wishes to know genetic risk for CRC. 
• A personal history of getting radiation to the abdomen or pelvic area to treat prior cancer. 
• Personal history of inflammatory bowel disease (Ulcerative Colitis or Crohn’s disease). 

Clinical Utility

• The genetic and molecular diagnosis for an accurate clinical diagnosis of a patient with personal or family history suggestive of a hereditary cancer syndrome.  
• Early initiation of treatment with a multidisciplinary team for appropriate total body screening, early surgical intervention, or pharmacologic treatment.  
• Risk assessment of asymptomatic family members according to the mode of inheritance  
• Reduce the incidence of advanced adenomas at colonoscopy. 
• Prevention of CRC. 
• Reduce morbidity related to CRC, or morbidity secondary to complications of surveillance and treatment. 
• Improved identification of hereditary CRC syndromes. 
• Improved pathways from diagnosis to treatment in susceptible populations. 

Genes & Diseases