The Importance of Knowing What’s In Your Genes by Justine Cooper

Today is Lynch Syndrome Awareness Day and we’re thrilled to share a guest post, written by Genetic Counselor, Justine Cooper. Thanks for sharing this information, Justine! We appreciate you and your advocacy!

Many people may not consider having colon cancer screenings because they don’t have a family history of colon cancer and think that they are not at risk to develop it. Did you know that 60-80% of people who are diagnosed with colon cancer have no family history of the disease? This means that even if no one in your family has ever had colon cancer, you still have a chance to develop it.

The average person has about a 6% chance to develop colon cancer at some point during their lifetime. Because of this, colonoscopies are recommended for everyone at 50 years of age, even if you have no family history of cancer. For African Americans, screening should begin at 45 years of age. For individuals who have personal risk factors (such as irritable bowel disease) or a family history of colon cancer, screening may be recommended earlier and more frequently.

While the majority of colon cancers are sporadic, we know that approximately 5% of colon cancers are hereditary and are caused by a genetic change that can be passed down through families. Individuals with hereditary colon cancer have a significantly higher chance to develop colon cancer and are more likely to develop it before 50 years of age.

Many people have heard of genetic tests for breast cancer, thanks in part to Angelina Jolie making headlines in 2013 after she underwent genetic testing for breast cancer; however most people don’t know that there are similar genetic tests for colon cancer. This testing isn’t recommended for everyone but may be considered in families where multiple people on the same side of the family have had colon cancer, particularly if family members have been diagnosed at young ages ( The most common cause of hereditary colon cancer is Lynch syndrome. Lynch syndrome can be passed down in families and drastically increases the risk for colorectal, uterine, ovarian, stomach, and other cancers. It’s estimated that approximately 1 in 350 people have Lynch syndrome, but many of them don’t know it. If a person has a gene mutation that causes Lynch syndrome, they have a 50% chance to pass the mutation on to each of their children. For individuals who are known to have Lynch syndrome, we can offer additional screenings, surgeries, and management options in order to find cancer at an early stage or to reduce the chance of ever developing cancer.

Genetic testing isn’t recommended for everyone with colon cancer, but depending on your personal or family history it may be something you want to consider. Testing is typically recommended for everyone who has been diagnosed with colon cancer before 50 years of age, even if no other family members have had cancer. If you have three relatives on the same side of the family who have had a Lynch syndrome-associated cancer (colorectal, uterine, ovarian, stomach, brain, bile duct, urinary tract, or pancreatic cancer), genetic counseling is indicated and genetic testing may be warranted, depending upon the family history.

Knowledge is power and knowing that someone has Lynch syndrome means that they will benefit from additional screenings, such as colonoscopies starting at 20-25 years of age and repeating the screening annually (instead of starting at age 50 and repeating every 10 years like individuals in the general population). Women with Lynch syndrome may consider having their uterus and ovaries removed in order to drastically lower their chances of developing uterine and ovarian cancer. Individuals who know they have Lynch syndrome can take steps to ensure that they are reducing their chances of developing cancer during their lifetime. In addition, they can give their family members the knowledge and tools that they need in order to take control of their health.

If you’re wondering whether you may benefit from genetic counseling or testing, you can talk to your physician to help decide whether a referral for genetic counseling might be appropriate. You can find a genetic counselor near you by using the “Find a Genetic Counselor” feature at A genetic counselor can help determine whether genetic testing is appropriate, discuss the pros and cons of testing, facilitate the testing, and come up with a management plan that takes both your genetic testing results and family history into account.

Justine Cooper is a board-certified Genetic Counselor. She serves as the Genetic Counselor Supervisor at the Markey Cancer Center at the University of Kentucky.