Certain traits such as being tall or short or having brown eyes or blue eyes are hereditary and are passed on from one generation to another. What you may not realize is that about 10% of many cancers may be related to heredity. Alterations or mutations in genes that can be passed down from generation to generation may cause an increased risk for certain types of cancer. Blood tests are available to determine if you are at greater risk than usual for breast, ovarian, colon, uterine, and other cancers.
For instance, if you carry certain mutations in genes known as BRCA 1 or BRCA 2 genes, you may have up to 87% lifetime risk to develop breast cancer as well as up to 44% lifetime risk to develop ovarian cancer. Without the mutation, your lifetime risk for breast cancer is about 8% and for ovarian cancer about 2%. Other gene mutations can increase lifetime risk for colon cancer up to 82% and for uterine cancer up to 71%. For the general population, the lifetime risk for colon or uterine cancer is 1.5% to 2%.
It is not appropriate for everyone to be tested for these gene mutations. The testing is not intended for the general population. If you or members of your family have any of the following diagnoses, you may be a good candidate for genetic testing:
- Breast cancer diagnosed before age 50
- Ovarian cancer at any age
- Bilateral breast cancer
- Both breast and ovarian cancers
- Male breast cancer at any age
- Ashkenazi/Eastern European descent
- Colon/rectal cancer before age 50
- Uterine (endometrial) cancer
- Several family members with colon cancer
- Stomach or ovarian cancer
Someone in your family has been diagnosed with a known genetic mutation that places them at higher than usual risk for cancer
Genetic testing will not tell you if you have cancer but will help to determine your risk for cancer and help determine steps that can be taken to decrease your risk.
If you test positive for a mutation, there are successful strategies now in use that can decrease your risk of developing cancer. These options may include taking medications or undergoing preventive surgeries. Even if you are unwilling to take medications or undergo preventive surgery, you can at least be monitored closely so that if a cancer does develop, it can be detected early while it is still curable.
Knowing your risk for cancer and doing everything you can to lower it can make a big difference for you, your family, and your future healthcare choices. The first step is to take a look at your family history. Talk to family members to determine who has had cancer, what type of cancer they had, and how old they were when diagnosed.
Talk to your health care provider if you think hereditary cancer risk assessment may be appropriate for you. When referred for genetic testing, your family history will be reviewed to be certain you are a candidate for the test.
Management options available for you, if you test positive, will be reviewed so that you will be well-informed. There will be an explanation of what the test results will mean to you, whether positive or negative. You will hear how your test results will help determine if other family members should be tested. Privacy laws will be discussed to assure you that the use of genetic test results cannot be used to determine eligibility or rates of health insurance. (State and Federal laws prohibit health insurance discrimination based on genetic information).
Most insurances cover hereditary cancer risk assessment, with the majority of patients paying a coinsurance of 10% or less. Many patients’ tests are covered 100%.
Even if there is a strong family history of breast, ovarian, colon, or uterine cancer in your family, cancer is not inevitable. Learning about your risk for developing one of these cancers may be helpful in preventing it or at least in helping to detect it early. Discuss your family history of cancer with your physician at your next appointment.
By Debra Gillett, F.N.P., R.N., AOCNP