Lynch Syndrome

Fact: Lynch syndrome is inherited through families

What is Lynch Syndrome?
Lynch syndrome 
is an inherited condition that causes an increased risk of developing cancer. Individuals with Lynch syndrome have a higher risk of developing colon and rectal cancer, as well as cancers of the stomach, small intestine, liver, gallbladder ducts, upper urinary tract, brain, skin, and prostate. Women with Lynch syndrome also have a high risk of developing uterine cancer (also called endometrial cancer) and ovarian cancer.

Even though the disorder was originally described as not involving noncancerous (benign) growths (polyps) in the colon, people with Lynch syndrome may occasionally have colon polyps.

People with Lynch syndrome may experience:

  • Colon cancer that occurs at a younger age, especially before age 50
  • A family history of colon cancer that occurs at a young age
  • A family history of cancer that affects the uterus (endometrial cancer)
  • A family history of other related cancers, including ovarian cancer, kidney cancer, stomach cancer, small intestine cancer, liver cancer, sweat gland cancer (sebaceous carcinoma) and other cancers

Lynch syndrome is caused by a problem in one of five genes in your DNA. These are the genes that affect how well your cells can spot mistakes and fix them as they grow and multiply.

When you have Lynch syndrome, your cells don't fix the errors. They make more and more flawed cells. Over time, that can cause cancer.

Lynch syndrome cancer risk is inherited in an autosomal dominant pattern, which means one inherited copy of the altered gene in each cell is sufficient to increase cancer risk. It is important to note that people inherit an increased risk of cancer, not the disease itself. Not all people who inherit mutations in these genes will develop cancer.

Other Cancer Risks
Lynch syndrome is the most common reason women develop cancer of the uterus. It also can raise your risk of these types of cancer:

  • Brain
  • Gall bladder ducts
  • Liver
  • Ovaries
  • Pancreas
  • Skin
  • Small intestine
  • Stomach
  • Sweat gland
  • Upper urinary tract

If you have Lynch syndrome, you're also more likely to get non-cancer growths called polyps inside your colon. Polyps are common in older people, but people with Lynch syndrome may get them earlier in life.

Genetic Tests and Counseling
If you have Lynch syndrome, there's about a 50% chance your child will get the faulty gene. To see if you have it, you can get a genetic test, which is done with a blood test. Your doctor can refer you to a genetic counselor to talk with you about your risks and options.

If you or someone in your family gets cancer, the doctor can do one of these tests on a small sample of the tumor to look for signs of Lynch syndrome:

  • Immunohistochemistry (IHC) tests use dye to mark proteins in the tumor sample. If certain proteins aren't there, it's a sign of Lynch syndrome.
  • Microsatellite instability (MSI) tests actually look at the DNA in the tumor tissue. This test can show if there are errors in your genes that point to Lynch syndrome.

Tumors that were taken out a few years before also can be tested. Hospitals may store tumor samples after surgery in case they need to be tested later.

Treatments and drugs
Colon cancer associated with Lynch syndrome is treated similarly to other types of colon cancer. However, surgery for Lynch syndrome colon cancer is more likely to involve the removal of more of the colon, since people with Lynch syndrome have a high risk of developing additional colon cancer in the future.

Cancer screening for people with Lynch syndrome
If you have Lynch syndrome, but haven't been diagnosed with an associated cancer — sometimes referred to as being a "previvor" — your doctor can develop a cancer-screening plan for you.

Research hasn't established which cancer screening tests are best for people with Lynch syndrome. As a result, medical groups vary on which tests they recommend. Which tests are best for you may depend on your family history and which gene is causing your Lynch syndrome.

As part of your cancer-screening plan, your doctor may recommend you have:

  • Colon cancer screening. A colonoscopy exam allows your doctor to see inside your entire colon and look for areas of abnormal growth that may indicate cancer. Colon cancer screening reduces the risk of dying of colon cancer by removing precancerous growths called polyps. People with Lynch syndrome typically begin colonoscopy screening every year or two starting in their 20s.
    People with Lynch syndrome tend to develop colon polyps that are more difficult to detect. For this reason, newer colonoscopy techniques may be recommended. High-definition colonoscopy creates more-detailed images and narrow band colonoscopy uses special light to create clearer images of the colon. Chromoendoscopy uses dyes to color colon tissue, which may make it more likely that the flat polyps that tend to occur more often in people with Lynch syndrome are detected.
  • Endometrial cancer screening. Women with Lynch syndrome may have an annual endometrial biopsy or ultrasound to screen for cancer beginning in their 30s.
  • Ovarian cancer screening. An ultrasound can be used to assess your ovaries and this may be recommended beginning in your 30s. By comparing annual ultrasound images, your doctor may be able to see changes to your ovaries that may indicate cancer. Your doctor may also recommend annual blood tests.
  • Urinary system cancer screening. Your doctor may recommend periodic screening for urinary tract cancers. Analysis of a urine sample may reveal blood or cancerous cells.
  • Gastrointestinal cancer screening. Your doctor may recommend endoscopy screening for stomach cancer and small intestine cancer. An endoscopy procedure allows your doctor to see your stomach and other parts of your gastrointestinal system.

Want to learn more?
The following are organizations and/or websites dedicated to providing information and education surrounding Lynch Syndrome These organizations are dedicated to research, education, awareness, and/or support. They are listed in Alphabetical order without any preference or prejudice. Listing these organizations is not a recommendation or referral in any regard for seeking treatment or consultation or support for treatment.

Lynch Syndrome International
Mayo Clinic
GARD (Genetic and Rare Diseases Information Center

Information on this page taken directly from:
Mayo Clinic
GARD (Genetic and Rare Diseases Information Center