What You Need to Know About Lynch Syndrome

Lynch syndrome (aka hereditary nonpolyposis colorectal cancer) is the most common hereditary colorectal cancer syndrome. If colorectal cancer genes run in your family, you or your children, siblings and parents may all be at high risk for developing colorectal and various associated cancers. So, should you talk to your health care provider about genetic testing for Lynch?

What is Hereditary Colon Cancer?

Globally, one out of 6 deaths are caused by cancer. Some cancers are hereditary, others related to lifestyle (i.e. tobacco), and many we don’t know the cause of. Some are inevitable, while others are potentially preventable. Colorectal cancer is the second leading cause of cancer related deaths in the US in men and women combined and is rising in younger patients with many being diagnosed long before they reach cancer screening age. But for most patients, colorectal cancer is preventable through colorectal cancer screening (colonoscopy) – and globally the incidence of colorectal cancer is actually decreasing due to colorectal cancer screening protocols. The majority of colorectal cancers are sporadic – meaning they occur in people who have no family history of colorectal cancer – while 5% are due to an inherited cancer syndrome that is passed down generation to generation through genes.

You may have Lynch if you have been diagnosed with colorectal cancer and:


  1. You are younger than 50 years
  2. You have personally been diagnosed with 2 colorectal cancers, or colorectal cancer and uterine, ovarian, stomach, pancreas, small intestine, kidney, ureter, bile duct, or brain cancer
  3. You have a first degree relative (parent, sibling, child) diagnosed at age 50 or younger with colorectal, uterine, ovarian, stomach, pancreas, small intestine, kidney, ureter, bile duct, or brain cancer
  4. You have 2 or more first- or second-degree relatives diagnosed within colorectal, uterine, ovarian, stomach, pancreas, small intestine, kidney, ureter, bile duct, or brain cancer

Lynch syndrome may affect your family even if you don’t have a personal history of cancer, but:

  1. 3 members of your family have had colorectal, uterine, ovarian, stomach, pancreas, small intestine, kidney, ureter, bile duct, or brain cancerand
  2. One is younger than 50 years old

Does Cancer Run In Your Family?

If you have family members diagnosed with a cancer under age 50, or multiple members of the family have had cancer, there may be a hereditary syndrome that runs in your family. And why would you want to know that information? Because you can then pursue appropriate screening to prevent cancer in yourself, your siblings and children. A simple saliva or blood test can give you the answer and keep you cancer free!Make sure you talk to you family members about your family history of cancer and discuss your history with your health care provider.

Lastly don’t forget that if someone in your family has been told that they have Lynch Syndrome, you may qualify for genetic testing and early screening for colorectal and other cancers.

Families with Lynch Syndrome should begin colonoscopy screening in their 20s or 5 years younger than the age of diagnosis of the youngest affected member. This is significantly earlier than age 40, when most patients with a family history of colorectal cancer without a hereditary cancer syndrome are recommended to begin screening.

Karen Zaghiyan, MD

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