What is Lynch Syndrome?
Lynch Syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), is a genetic disorder that significantly increases the risk of developing various types of cancer. It is most commonly associated with colorectal cancer, but it also increases the risk of other cancers, such as endometrial, ovarian, and gastric cancers.
How is Lynch Syndrome Inherited?
Lynch Syndrome is inherited in an autosomal dominant pattern. This means that a person only needs to inherit one copy of the mutated gene from one parent to be at increased risk. The syndrome is caused by mutations in one of several mismatch repair (MMR) genes, including MLH1, MSH2, MSH6, PMS2, and EPCAM.
How is Lynch Syndrome Diagnosed?
Diagnosis often begins with a detailed family history and clinical evaluation. If Lynch Syndrome is suspected, genetic testing can be performed to identify mutations in the MMR genes. Additionally, microsatellite instability (MSI) testing and immunohistochemistry (IHC) of tumor tissue can help detect abnormalities that suggest Lynch Syndrome.
Colonoscopy starting at age 20-25, repeated every 1-2 years
Endometrial biopsy and transvaginal ultrasound annually starting at age 30-35
Screening for ovarian cancer, although no standardized guidelines exist
Upper endoscopy every 3-5 years starting at age 30-35 for gastric cancer
What are the Treatment Options for Lynch Syndrome-Associated Cancers?
Treatment options depend on the specific type and stage of cancer but may include surgery, chemotherapy, radiation therapy, and immunotherapy. For colorectal cancer, prophylactic colectomy might be considered to reduce cancer risk. For women at high risk of endometrial and ovarian cancer, prophylactic hysterectomy and oophorectomy may be recommended.
Can Lynch Syndrome be Prevented?
While genetic predisposition cannot be changed, cancer risk can be managed through regular screening, lifestyle modifications, and prophylactic surgeries. Genetic counseling is also crucial for individuals with Lynch Syndrome and their families to understand their risks and options.
Why is Genetic Counseling Important?
Genetic counseling provides individuals and families with information about the risks, benefits, and limitations of genetic testing. It helps them understand how Lynch Syndrome can affect their health and guides them in making informed decisions about screening and preventive measures.
