Lynch syndrome

Lynch syndrome is a hereditary condition that makes you more likely to develop cancer. Also known as hereditary nonpolyposis colorectal cancer syndrome (HNPCC) and Muir-Torre syndrome, it’s a common cause of increased cancer risk due to genetic factors, with approximately one in 270 people affected.

Not every person with Lynch syndrome develops cancer, but the odds of developing cancer are much greater than average. Those with Lynch syndrome are most likely to develop colorectal cancer and uterine (endometrial) cancer, though they have higher chances of getting other cancers too.

Fortunately, interventions are available through cancer genetics and risk evaluation, active monitoring, and specialized medical care. At Penn Medicine, the King Center for Lynch Syndrome at the Abramson Cancer Center is a hub for patient care and research, providing access to state-of-the-art, compassionate care and proactive health management for individuals and families affected by Lynch syndrome.

There aren’t any symptoms of Lynch syndrome itself. You may have symptoms associated with specific types of cancer that develop due to increased cancer risk.

If Lynch syndrome runs in your family, your doctor may actively screen and monitor you for symptoms associated with cancers linked to Lynch syndrome, like colorectal cancer, endometrial (uterine) cancer, small intestinal cancer, and others.

The following tables summarize the increased cancer risks for people with Lynch syndrome. Different gene mutations carry varying risks of developing certain cancers.

The only way to diagnose Lynch syndrome is through genetic testing. A Lynch syndrome specialist can tell you if testing is right for you. Taking this step may be appropriate if:

• You’ve been diagnosed with colon cancer or uterine cancer before age 50.
• You’ve had a history of more than one Lynch syndrome-associated cancer (for example, colon cancer plus uterine cancer).
• Multiple family members have had Lynch syndrome-associated cancers.
• A family member has been diagnosed with Lynch syndrome.
• You’ve had a tumor with features suggestive of Lynch syndrome (for example, an abnormal result on mismatch repair immunohistochemistry, also known as an MMR-IHC test).

Given the multiple increased cancer risks for those with Lynch syndrome, it’s important to seek care from a team of providers with expertise in this condition. They’ll guide you through the appropriate screening and risk reduction strategies, like getting a colonoscopy.

At Penn Medicine, you’ll meet with a specialist annually to review your personal and family medical history and genetic testing results. Your individualized Lynch syndrome management plan will include recommendations for cancer screening and risk reduction options. This includes active monitoring for gastrointestinal tract cancer (colorectal, gastric, small intestinal, pancreatic), gynecologic cancer, urinary tract cancer, and skin cancer, among others.

Your care plan extends to other areas of your life too, including family planning and genetic testing of potentially at-risk relatives. You may also be advised on taking medications to decrease cancer risk (chemoprevention). We stay up to date with the latest advancements in Lynch syndrome care to help you assess your risks, monitor your health, and make informed decisions so you can live well and navigate your options with confidence.