Hereditary Colorectal Cancer

Who is at risk for colorectal cancer?

Everyone is at risk for colorectal cancer; the risk varies based on multiple factors including:

• age
• presence of an inherited mutation
• personal and family history of cancer
• other risk factors

How common is colorectal cancer?

In the general population, the risk for colorectal cancer is about 4%. This means that 1 out of every 25 people will develop colorectal cancer in their lifetime. 

For people with an increased risk for colorectdal cancer, the lifetime risk may be much higher. 

Is colorectal cancer genetic?

All colorectal cancers are caused by damage to genes in the cells of the colon or rectum. Most of this damage happens during the course of a person's lifetime. 

Some colorectal cancers are hereditary. These are caused by inherited mutations that are present at birth and can be passed on from parents to their children. Genetic counseling and testing can help people learn if they are at high risk. 

What are the signs of hereditary colorectal cancer?

Genetic testing and biomarker testing can determine if colorectal cancer is hereditary. Some of the more common signs of hereditary colorectal cancer include:

• young onset cancers (diagnosed before age 50)
• multiple cancer diagnoses in the same person
• multiple people in a family with colorectal, endometrial or other types of cancer

You can read more about colorectal cancer genetic testing here. 

Which genes are linked to hereditary colorectal cancer?

Inherited mutations in the genes listed below are linked to an increased risk for colorectal cancer. 

How common is hereditary colorectal cancer?

About 10% of all colorectal cancers are caused by inherited mutations that can be passed on from parents to their childrens. 

What else affects colorectal cancer risk?

Factors such as diet, weight, exercise, smoking and alcohol consumption can affect colorectal cancer risk in the general population and in people at high risk for cancer. More research is needed to understand how much these factors influence risk in people with inherited mutations.

What can people do to manage their colorectal cancer risk?

There are three main medical approaches to managing an increased colorectal cancer risk: 

• increased screening
• medications to lower risk
• risk-reducing surgery

Each of these options comes with benefits, costs and risks. Expert guidelines for colorectal cancer risk management are based on your level of risk.

What type of colorectal cancer screening is best for high-risk people?

Colonoscopy is considered the best screening method for people at high risk for colorectal cancer. Experts guidelines for screening differ based on a person's age, gender, lifetime risk, breast density and other factors. Visit this page for more information. 

How are hereditary colorectal cancers different?

Hereditary colorectal cancers are more likely to occur at a young age. They are also more likely to test positive for the biomarkers MSI-High or dMMR (also known as MMR-D). Colorectal cancers with these biomarkers are more common in people with Lynch syndrome.  You can learn more about treatment options for MSI-High and dMMR colorectal cancers here.