From the Guidelines
Lynch syndrome is a genetic condition that significantly increases the risk of colorectal, endometrial, and other cancers, and individuals with this condition should undergo regular cancer screenings starting at an earlier age than the general population, with colonoscopies beginning at age 20-25 and repeated every 1-2 years, as recommended by the most recent guidelines 1.
Key Recommendations
- People with Lynch syndrome should undergo regular cancer screenings, including colonoscopies, starting at age 20-25 and repeated every 1-2 years.
- Women with Lynch syndrome should also have endometrial and ovarian cancer screenings beginning at age 30-35.
- Additional recommended screenings include upper endoscopy every 3-5 years starting at age 30-35 and urinalysis with cytology annually beginning at age 30-35.
- Family members of individuals with Lynch syndrome should consider genetic testing to determine if they also carry the mutation.
- Risk-reducing surgeries, such as removal of the colon or uterus and ovaries, may be considered for high-risk individuals.
Importance of Early Detection
Lynch syndrome accounts for about 2-4% of all colorectal cancers, and affected individuals have up to an 80% lifetime risk of developing colorectal cancer if not monitored appropriately 1. Early detection and prevention of cancer are crucial for individuals with Lynch syndrome, and regular screenings can help identify cancers at an early stage when they are more treatable.
Genetic Testing
Genetic testing is essential for identifying individuals with Lynch syndrome, and it can help determine the risk of developing certain cancers 1. The most common genes associated with Lynch syndrome are MLH1, MSH2, MSH6, PMS2, and EPCAM, and genetic testing can detect mutations in these genes.
Management and Surveillance
The management and surveillance of Lynch syndrome involve a multidisciplinary approach, including regular cancer screenings, genetic testing, and risk-reducing surgeries 1. The goal of management and surveillance is to prevent or detect cancers at an early stage, reducing the risk of morbidity and mortality associated with Lynch syndrome.
From the Research
Definition and Causes of Lynch Syndrome
- Lynch syndrome is an autosomal dominant familial cancer risk syndrome that occurs due to a germline mutation in one of several mismatch repair genes, including MLH1, MSH2, MSH6, or PMS2 2.
- It is also known as hereditary nonpolyposis colorectal cancer (HNPCC) syndrome 3.
Risks Associated with Lynch Syndrome
- Individuals with Lynch syndrome have a 50%-70% lifetime risk of colorectal cancer, 40%-60% risk of endometrial cancer, and increased risks of several other malignancies 2.
- The risk of endometrial cancer equals or exceeds that of colorectal cancer in women with Lynch syndrome 4.
- Ovarian cancer risk in women with Lynch syndrome is 6-8% 5.
Screening and Prevention
- Screening for colorectal cancer in Lynch syndrome enables early detection and likely cancer prevention 6.
- Current gynecologic cancer screening guidelines for women with Lynch syndrome include annual endometrial sampling and transvaginal ultrasonography beginning at age 30 to 35 years 3.
- Prophylactic hysterectomy with bilateral salpingo-oophorectomy performed after the completion of childbearing may be offered for gynecologic cancer prevention 4.
- Prevention options also include the use of oral contraceptives, which are known to be highly effective for decreasing risk of both endometrial and ovarian cancer in the general population 5.
Diagnosis and Identification
- A combination of family and personal medical history and tumor testing provides an efficient basis for diagnosing Lynch syndrome in women with endometrial cancer 3.
- Microsatellite instability testing and/or immunohistochemical testing can be used to identify tumor mismatch repair deficiencies 2.
- Universal screening is not standard across institutions, and variation exists regarding the optimum method for tracking and disclosing results 2.