Lynch syndrome (LS), also known as Hereditary Non-Polyposis Colorectal Cancer (HNPCC), is the most common hereditary colorectal (CRC) cancer predisposition syndrome. It is an autosomal dominant condition that causes a significant increased lifetime risk of CRC and endometrial (uterine) cancer in addition to other cancers. Individuals suspected of having LS should be referred for a genetic consultation for consideration of genetic testing. Screening, surveillance and management of CRC and other cancers should be guided by genetic test results and/or family/ personal history. Studies show that conversations between patients and their healthcare providers are the strongest driver of screening participation. (For more information see the GEC-KO Messenger).
This point of care tool has two parts. The first part contains three questions for your patient that will better help you stratify his/her risk for hereditary colorectal cancer and to identify those that would benefit from a referral for genetics consultation. The cumulative sensitivity of these three questions in identifying patients with characteristics suggestive of the hereditary colorectal cancer syndrome, Lynch syndrome (LS), and those who should undergo a more extensive risk assessment is 77%. When all 3 questions are answered “yes,” the tool correctly identifies 95% of individuals with germline mutations causing LS.1 If a patient answers “yes” to all of these questions a referral to genetics should be offered. If a patient answers “yes” to any of these questions, consider further assessment using the criteria in Part II. Part II contains further personal and family history Red Flags to identify those at high risk of LS most likely to benefit from a referral to genetics. These red flags are derived from the Amsterdam criteria [with 22% sensitivity and 98% specificity for LS] and the revised Bethesda criteria [with a 82% sensitivity and 77% specificity for LS].2
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 Kastrinos F, Allen JI, Stockwell DH, et al., Development and validation of a colon cancer risk assessment tool for patients undergoing colonoscopy. Am J Gastroenterol 2009; 104: 1508–1518.
 Giardiello FM, Allen JI, Axilbund JE et al., Guidelines on genetic evaluation and management of Lynch syndreom: A consensus by the US multi-society task force on colorectal cancer. Dis Colon Rectum 2014; 57: 1025–1048
GEC-KO aims to aid the practicing non-genetics health professional by providing informed opinions regarding genetic/genomic conditions, services and technologies that have been developed in a rigorous and evidence-based manner with periodic updating. The content on the GEC-KO site is for educational purposes only. No resource should be used as a substitute for clinical judgement. GEC-KO assumes no responsibility or liability resulting from the use of information contained herein.