|The ASCRS Executive Council has endorsed guidelines developed by a Multi-Society Task Force in collaboration with invited experts to assist health care providers with the appropriate provision of genetic testing and management of patients at-risk for and affected-with Lynch Syndrome.
The Multi-Society Task Force Guidelines provide:
- a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting;
- a strategy for universal screening of patients diagnosed with colorectal cancer;
- a strategy for genetic testing in persons at-risk for Lynch syndrome;
- guidelines for screening at-risk and affected persons with Lynch syndrome;
- guidelines for the management of patients with Lynch syndrome.
The Multi-Society Task Force included representatives of three major gastroenterology professional organizations with a special interest in colorectal cancer: American College of Gastroenterology (ACG), American Gastroenterological Association Institute (AGAI), and the American Society for Gastrointestinal Endoscopy (ASGE).
About 70-80 percent of patients with colorectal cancer seem to have sporadic disease with no evidence of an inherited disorder. In the remaining 20-30 percent, a potentially definable inherited component may be causative.
Lynch syndrome (LS), an autosomal dominant condition, is the most common cause of inherited colorectal cancer. The eponym “Lynch syndrome” recognizes Dr. Henry T. Lynch, the first author on the original 1966 publication that described this condition.
In the early 1990s, mutations of genes in the DNA mismatch repair pathway were implicated in the cause of Lynch syndrome. Since then, the sensitivity of germline testing has increased, as additional genetic discoveries have occurred. When used appropriately, genetic testing for LS can confirm the diagnosis at the molecular level, justify surveillance of at-risk persons, decrease the cost of surveillance by risk stratification, aid in management, and help in decisions concerning family and career planning. However, when used inappropriately, genetic testing can misinform affected patients with false negative results and waste patient and societal resources.
The goal of the guidelines is to critically analyze the current literature and provide “best practice” evidence-based recommendations for diagnosis and management strategies to health care providers caring for these patients. The Task Force’s methodology began with an extensive, systematic literature review.
Some of the specific guidelines include:
Guideline: Testing for mismatch repair deficiency of newly diagnosed colorectal cancers (CRC) should be performed.
Guideline: Individuals who have a personal history of a tumor showing evidence of mismatch repair deficiency (unless there is a BRAF mutation or other evidence of MLH1 promoter methylation); uterine cancer diagnosed under age 50; a known family MMR gene mutation; fulfill Amsterdam criteria or guidelines; and/or have a personal risk of >5% chance of Lynch syndrome based on prediction models should undergo genetic evaluation for Lynch syndrome.
Guideline: Screening for colorectal cancer by colonoscopy is recommended in persons at-risk for or affected with LS every one to two years beginning between ages 20 to 25 or 2-5 years before the youngest age of diagnosis of colorectal cancer in the family if diagnosed before age 25.
Guideline: Routine screening of the small intestine is not recommended.
Guideline: Colectomy with ileorectal anastomosis is primary treatment of patients affected with LS with colorectal cancer or colorectal neoplasia not removable by endoscopy.
Guideline: Growing but not conclusive evidence exists that aspirin is beneficial in preventing cancer in LS patients. Treatment of an individual patient with aspirin is a consideration after discussion of patient-specific risks, benefits, and uncertainties of treatment is conducted.