Understanding your family’s medical history is more than just knowing who had what illness – it’s a key part of assessing your own risk for certain cancers, including colorectal cancer. Genetics can play a big role in this, and being informed can empower you to make proactive health decisions.
Cancer is a result of changes in genes that control the way our cells function, especially how they grow and divide. While most cancers are caused by genetic changes that occur during a person’s lifetime, some people inherit abnormal genes that can increase their risk of developing cancer. This is where family history and genetics come into play.
If many people in your family have had colon, rectal, or other types of cancer, it could mean a higher chance of getting cancer because of your genes. This is especially true if family members were diagnosed when they were young or if cancer happened in many generations. A family history of cancer or an inherited genetic condition doesn’t mean you will get cancer, but it does mean you may be at a higher risk and should begin screening before age 45.
Family History
Genetic testing can identify specific inherited mutations that increase the risk of cancer. If you have a strong family history of cancer, or if you are concerned about your risk, discussing genetic testing with a healthcare professional might be a good idea. It can provide valuable information for you and your family members. It can also help in making informed decisions about your health care.
Some families have a higher risk of cancer due to inherited gene mutations. These are often referred to as hereditary cancer syndromes. Here are a few common inherited cancer syndromes related to colorectal cancer:
Also known as hereditary non-polyposis colorectal cancer (HNPCC), Lynch syndrome is the most common herediatry cause of colorectal cancer and accounts for about 2-4% of all colorectal cases according to the American Cancer Society. In most cases, the inherited defect is in either the MLH1, MSH2, MSH6, PMS2 or EPCAM gene. However, there are other genes that can also cause Lynch syndrome. People with Lynch syndrome have a significantly higher lifetime risk of developing colorectal cancer, with many as high as 50%, depending on which gene is affected. They are also at increased the risk of other cancers, including endometrial, ovarian, stomach, and small intestine cancers.
Monitoring and Treatment
This is a rare inherited condition caused by mutations (changes) in the APC gene. This leads to the development of hundreds to thousands of polyps in the colon and rectum, often starting between the ages of 10 and 12. If untreated, nearly all individuals with classic FAP will develop colorectal cancer by age 40. This syndrome accounts for less than 1% of all colorectal cancer cases but carries a near 100% lifetime risk of developing the disease if left unmanaged. Individuals with FAP also have an increased risk of other cancers, including stomach, small intestine, pancreas, and liver.
Monitoring and Treatment
This is a rare hereditary condition caused by mutations in the MUTYH gene. Individuals with MAP may develop fewer polyps than those with FAP, but they still have an increased risk of colorectal cancer. This condition is typically inherited in an autosomal recessive pattern, meaning both copies of the gene must be mutated for the syndrome to occur and often leads to cancer at a younger age. Indivuduals with MAP also have an increased risk of other GI (gastrointestinal) tract, breast, ovary, bladder, and thyroid cancer.
Monitoring and Treatment
If genetic testing shows that you have a higher risk of cancer, there are proactive steps you can take. Regular screenings, lifestyle changes, and working closely with your healthcare team can help you stay ahead of the curve and manage your risk effectively.
