Genetic Counseling and Testing for Hereditary Colon Cancer Syndromes
Using a blood sample, a physician can often determine if a patient is at risk for hereditary cancer. Therefore, the patient and doctor can begin steps to reduce his or her risk and possibly prevent colorectal cancer.
What does it mean to have a hereditary colorectal cancer syndrome?
The majority of colorectal cancers are not a part of an underlying genetic syndrome. However, when there are many individuals in a family with a colorectal (or associated) cancer or when someone is diagnosed with a colorectal cancer at a young age, there is a possibility that an underlying genetic syndrome might be responsible.
There are also hereditary colorectal cancer syndromes that cause individuals to develop more colorectal polyps than are typically seen. When an individual has more than 10 polyps identified or if a polyp is found to be made up of particular cells, this too can put an individual at increased risk of having a hereditary colorectal cancer syndrome.
The most important thing you can do is to know your family history and talk with family members about whether or not anything unusual or suspicious was found on a colonoscopy. Armed with this information, your doctor and genetic counselor can give you the most appropriate care and personalized recommendations.
What should I know about my family history?
Many families with a hereditary colorectal cancer syndrome will have individuals in their family who have had a colorectal cancer but not all families.
Here are some other cancers that you should look for in your family if you are concerned about a hereditary colorectal cancer syndrome:
- Uterine/endometrial cancer
- Ovarian, pancreatic, thyroid cancers
- Other GI cancers (small intestines, stomach)
- Childhood brain tumor (medulloblastoma)
- Childhood liver cancer (hepatoblastoma)
There are also tests that can be performed on a cancer once it is removed that can sometimes indicate the presence of a hereditary colorectal cancer syndrome. If an individual has a cancer, knowing about tumor testing (called IHC and MSI) can also be helpful in evaluating a family.
What should I do if I am concerned about my family or personal history?
Genetic counseling offers you the opportunity to sit down and thoroughly review your family history and any medical records you may have. Through this evaluation you can learn more about whether or not your personal and/or family histories are indicative of a hereditary colorectal cancer syndrome.
If medically appropriate and desired by the patient, genetic testing can be a powerful tool in further evaluating whether or not a hereditary colorectal cancer syndrome is present. Genetic testing can be complicated, so a genetic counselor can help navigate questions regarding insurance coverage, interpreting testing results, and understanding clinical recommendations.
If you are concerned about your family or personal history, ask your doctor about whether or not you would benefit from genetic counseling.