The information on this page was reviewed and approved by
Maurie Markman, MD, President, Medicine & Science at CTCA.

This page was updated on May 26, 2021.

What is Lynch syndrome?

Lynch syndrome is an inherited condition, meaning that it’s caused by altered genes passed down from one's parents. Having Lynch syndrome increases the risk of developing many types of cancer as well as the chance of getting cancer before age 50.

Anyone with Lynch syndrome faces an especially high risk of colorectal cancer—about 4,000 cases of colorectal cancer are caused by Lynch syndrome every year, according to the U.S. Centers for Disease Control and Prevention (CDC). The condition is also called hereditary non-polyposis colorectal cancer (HNPCC).

Women with the condition also have an increased risk of endometrial cancer (cancer of the uterus). Lynch syndrome causes about 1,800 cases of endometrial cancer every year, according to the CDC. Other cancers that people with Lynch syndrome are more likely to develop are:

Mutations and family history

Lynch syndrome is common compared with other inherited cancer syndromes—it’s estimated that about one in 300 people have a gene mutation linked to the condition, according to the American Society of Clinical Oncology (ASCO).

People with Lynch syndrome have inherited changes (mutations) in particular genes, such as MLH1, MSH2, MSH6, PMS2 and EPCAM. When specific mutations are present in these genes, they don’t do their job properly, making it easier for cancer to develop. In people who don’t have Lynch syndrome, these genes play a role in repairing DNA, thus helping to prevent certain cancers.

Those with a strong family history of colorectal cancer or of Lynch syndrome should inform their doctor. Immediate family members of someone with Lynch syndrome have a 50 percent chance of also having the condition, according to the American Cancer Society. If Lynch syndrome is suspected because of family history, doctors may recommend genetic testing.

If genetic tests reveal a mutation associated with Lynch syndrome, doctors may recommend screening for colorectal cancer at a younger age. Likewise, women with Lynch syndrome may be advised to start screening for endometrial cancer.

Lynch syndrome and risks of developing cancer

Certain gene mutations associated with Lynch syndrome carry higher risks of cancer than others. Below find the estimated lifetime cancer risks for people with Lynch syndrome, according to ASCO.

  • Colorectal cancer: 20 percent to 80 percent
  • Liver/bile duct cancer: 1 percent to 4 percent
  • Stomach cancer: 1 percent to 13 percent
  • Small bowel cancer: 1 percent to 6 percent
  • Urinary tract cancer: 1 percent to 18 percent
  • Brain cancer: 1 percent to 3 percent
  • Pancreatic cancer: 1 percent to 6 percent
  • Endometrial cancer: 15 percent to 60 percent
  • Ovarian cancer: 1 percent to 38 percent

cancer care

AS 24 HRS.

CALL NOW: 888-552-6760