Lynch syndrome

Lynch syndrome is an inherited condition that greatly increases a person’s risk for developing colorectal cancer. It is the most common inherited form of colorectal cancer.

The facts

  • Three to five percent of all colorectal cancer patients are diagnosed with Lynch syndrome.
  • About one in 300 people have a harmful genetic mutation in their DNA that causes Lynch syndrome.
  • The average age of onset of colon cancer in Lynch syndrome patients is between 40-60, while the average age in sporadic (random) patients is between 67-71.
  • When one parent has Lynch syndrome, each child has a 50% chance of having Lynch syndrome.
  • Lynch syndrome increases the risk for several other types of cancer, including endometrial cancer (uterine cancer), ovarian cancer, gastric (stomach) cancer and other types of cancer.

Hereditary risks

Causes, risks, prediction, and diagnosis

woman with colon polyps medical illustration

Polyps with Lynch syndrome

  • If a polyp is found, it should be removed by endoscopy.
  • If a polyp cannot be removed by endoscopy, discuss with your doctor the surgical options best suited for you.
  • If an advanced polyp is found during your colonoscopy, discuss with your doctor the different surgical options most suited for you.
  • It is common for people with Lynch syndrome to have flat polyps that can be difficult to detect. Talk to your doctor about screening for these.
Bob Robes sitting in hospital bed

Treatment options for Lynch syndrome

Lynch syndrome patients with colon cancer are treated similarly to colon cancer patients without Lynch syndrome.

Depending on the stage of diagnosis, a typical treatment plan will include surgery, chemotherapy, and immunotherapy.

Lynch syndrome and cancer screening

People with Lynch syndrome should get screened early and often. Talk with your doctor about a screening plan to reduce your risk of developing colorectal or other cancers.

Early screening saves lives

Start at the age of 20-25, or two to five years younger than the youngest relative who was diagnosed with colorectal cancer.

Screen often

Continue with colonoscopy every one to two years until the age of 40, even if no polyps or pre-cancerous growths are found. Make sure to get a colonoscopy every year after 40.

male doctor with male patient

Other things to consider

  • Plan for annual total body skin exams, since skin cancer is associated with Lynch syndrome.
  • Some studies have shown that daily aspirin may reduce the risk of developing colorectal cancer and other types of cancer in people with Lynch syndrome. Ask your doctor before taking any new medication.
  • Some people with Lynch syndrome may consider surgically removing their whole colon (prophylactic colectomy), even before cancer is detected, to reduce the risk of developing colorectal cancer.
allycon 2022 three woman hugging

Women & Lynch syndrome

Women with Lynch syndrome should have a screening plan for endometrial cancer and ovarian cancer that includes an annual:

  • Transvaginal ultrasound
  • Blood test for the CA125 biomarker

Consider having surgery to remove your uterus (hysterectomy) and ovaries (oophorectomy) to reduce risk of endometrial and ovarian cancers.

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