Lynch syndrome testing in the Island

Lynch syndrome

Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC), is the most common cause of hereditary bowel cancer.

People with Lynch syndrome are more likely to get bowel cancer and other cancers, and at a younger age (before 50), including

  • Uterine (endometrial),
  • Stomach,
  • Liver,
  • Kidney,
  • Brain, and
  • Certain types of skin cancers.

Genetics and Lynch syndrome

Lynch syndrome is due to inherited changes (mutations) in genes that affect DNA mismatch repair, a process that fixes mistakes made when DNA is copied. These genes (MLHLMSH2MSH6PMS2, and EPCAM) normally protect you from getting certain cancers, but some mutations in these genes prevent them from working properly.

Everyone has two copies of each of the genes involved in Lynch syndrome, one from their mother and one from their father. Even if a person inherits a mutation in a Lynch syndrome gene, they still have the normal copy of the gene from the other parent. Cancer occurs when a second mutation affects the normal working copy of the gene, so that the person no longer has a copy of the gene that works properly. Unlike the inherited Lynch syndrome mutation, the second mutation would not be present throughout the person’s body, but would only be present in the cancer tissue. However, not everyone with Lynch syndrome will get cancer.

Bowel cancer also can be caused by mutations in genes other than those related to Lynch syndrome. This means that some families with a history of bowel cancer will not have mutations in a Lynch syndrome gene. These mutations might be picked up through genetic testing using multigene panels, which look for mutations in several different genes at the same time.

Family health history is important

You and your family members are more likely to have Lynch syndrome if your family has a strong history of bowel cancer. Family members who inherit Lynch syndrome usually share the same mutation. If one of your family members has a known Lynch syndrome gene mutation, other family members who get genetic testing should be checked for that mutation.

Noble’s Hospital Histopathology Department now tests all biopsy specimens of bowel cancer tumours to see if Lynch syndrome is likely. Depending on the results, further genetic testing follows NICE guidelines with samples referred to specialist centres in the UK.  Based on an annual incidence of 80 cancers on the IOM 10-12 samples will be submitted for genetic testing with 1-2 then needing further DNA analysis for confirmation of Lynch syndrome.

Noble’s has looked at pathways whereby families of those affected by Lynch Syndrome are offered genetic (blood) testing. This testing can only be done if a person is willing to have it and it is important to be aware that not everybody in a family will have the same feelings about genetic testing.  As people with Lynch syndrome have an increased risk of cancer, more regular screening tests are recommended for bowel and endometrial cancer as these can improve outcomes if problems are diagnosed at an early stage meaning the person may need less invasive, lower cost treatment.

Bowel Cancer Isle of Man is proud to be associated with this ground breaking procedure.