Your family history could be a risk factor if one or more of the following statements are true for either side of your family—your mother's or your father's. Generally, the more that are true, the greater the risk.
- One or more of your blood relatives have developed the same cancer or related types of cancer (for example, breast, and ovarian).
- One or more of your affected family member(s) are your first-degree relatives (parent, brother, sister, daughter, son). The closer your relation to individuals who have cancer, the greater the possibility that heredity may be a risk factor for you.
- Any cases of cancer were diagnosed before age 50. Because most cancers develop when people are in their 50s, 60s, or older, younger diagnosis suggests the possibility of inherited risk.
- Any family member has been diagnosed with cancer more than once, or has had two different types of cancer.
Share this information with your doctor. If he or she feels that you have a strong family history, based on the above criteria, you may wish to consider the possibility of genetic testing to find out whether or not you are at higher-than-average risk. See Questions to Ask Your Doctor.
Building a Family History
Considering Genetic Testing
Costs, Insurance Coverage, and Privacy Concerns
Benefits and Drawbacks of Testing
Building a Family History
An important next step is to talk to other relatives to form a more complete picture of your family's cancer history. Remember that your family history comes from both sides of your family—your mother's and your father's. You will want to gather as complete information as possible for all of their close relatives. In addition, ethnic background can sometimes be an important factor influencing genetic risk. The history should include information about cancer, as well as any other significant health problems.
In addition to speaking with relatives and your doctor, you should meet with a certified genetic counselor. This is a nurse, doctor, or other health professional specially trained to provide information and advice about family-related risk for diseases and health conditions. Meeting with a genetic counselor is absolutely essential if you think there is any possibility you will want to have genetic testing.
The genetic counselor will help you build a family tree based on information you provide about the pattern of cancer in your family—who was affected and the ages at which they were diagnosed. Based on this and your personal health history, he or she can help you assess your risk and determine whether genetic testing is warranted.
To find a licensed genetic counselor, you can:
- Search the National Cancer Institute's online directory at www.cancer.gov/search/genetics_services or call 1-800-4-CANCER.
- Use the National Society of Genetic Counselors (NSGC) "Find a Counselor" search at www.nsgc.org, or call 312-321-6834.
- Check with your doctor or cancer centers in your area.
For more tips about how to find a genetic counselor, see Finding a Qualified Genetic Counselor.
Whether or not you decide to undergo genetic testing, a strong family history alone can put you at higher-than-average risk of developing cancer. For example, a woman whose mother, sister, or daughter (all first-degree relatives) has had breast cancer is about twice as likely to develop breast cancer as a woman whose close female relatives have not had breast cancer. A man who has a father or brother diagnosed with prostate cancer is one-and-a-half to three times more likely to develop the disease than a man with no family history.
Considering Genetic Testing
Scientists have developed tests that can help families determine whether they are carrying certain genetic mutations that increase their risk for different types of cancer. If a person who has been diagnosed with cancer is found to have the mutation, then his or her family members could have it as well—putting them at much greater risk of eventually developing the disease.
When you meet with a genetic counselor, he or she will not only help you compile a family health history, but also make sure that you understand:
- The benefits and limits of testing
- How to interpret the results
- What you can do with those results
You should come to the session prepared to bring up your concerns about genetic testing. In fact, your questions should guide the discussion. Here is a list of suggested questions to ask the genetic counselor.
The table below lists many of the genetic tests that are currently available. Note that there are other cancers that can be linked to family history, such as prostate cancer, but for which no genetic test is currently available.
| Condition or Cancer Type |
Testing Looks for . . . |
|
Hereditary breast and ovarian cancer syndrome: A condition in which multiple family members are affected with breast cancer, ovarian cancer, or both.
|
BRCA1 and BRCA2 gene mutations. |
|
Familial adenomatous polyposis: Family members develop hundreds of precancerous growths (polyps) in the colon and rectum that lead to cancer. |
APC gene mutation. It increases risk for colorectal cancer and some other cancers, such as stomach cancer. |
|
Hereditary nonpolyposis colorectal cancer (HNPCC): Family members have multiple colorectal cancer cases not related to polyps. Other types of cancer tend to appear in the family as well. |
Mutations in a group of genes that are associated with increased risk for colorectal and other forms of cancer, such as endometrial (the lining of the uterus), stomach, small intestine, liver, brain, and ovary. |
|
Multiple endocrine neoplasia type 2: An inherited condition that increases risk for a type of thyroid cancer, medullary thyroid carcinoma. |
RET gene mutation. |
|
Melanoma: An often aggressive form of skin cancer. |
P16 gene mutation. |
|
Retinoblastoma: A childhood cancer that affects the eye. |
Rb tumor suppressor gene mutation. This increases risk for osteosarcoma (bone cancer) of the leg and the bone around the eye. |
|
Li-Fraumeni syndrome: A condition that increases risk for breast cancer, sarcoma, leukemia, and tumors of the adrenal gland and central nervous system. |
P53 gene mutation. |
|
Von Hippel-Lindau syndrome: A rare condition in which individuals are at higher risk of a cancer that affects the kidney, as well as noncancerous tumors in the brain and spine, the retina, and the adrenal gland. |
VHL gene mutation. |
To read more detailed guidelines on who should be tested for cancer susceptibility, see Genetics Testing: Benefits, Limitations, and Keeping Results Private.
Costs, Insurance Coverage, and Privacy Concerns
A genetic test can cost anywhere from a few hundred to a few thousand dollars. Your health insurance plan may cover the cost if you meet criteria indicating that cancer runs in your family. Because policies vary, you will need to check your own plan's details.
Some people prefer to pay for the test themselves because they do not want their insurers to know they may be at higher risk of developing cancer. They fear that their insurer or even their employer may treat them differently as a result.
Fortunately, reports of discrimination based on cancer risk are rare. Most, but not all, states have laws preventing insurance companies and employers from discriminating based on a hereditary risk for disease. Many also have laws protecting the privacy of your genetic information. You can research your state's laws through the National Conference of State Legislatures website.
The Health Insurance Portability and Accountability Act (HIPAA) also offers some protection to members of group health plans. The Genetic Nondiscrimination Act of 2005, which would prohibit insurers from discriminating based on genetic risk, is still making its way through Congress.
If you are concerned about issues of privacy and discrimination, talk to your genetic counselor. He or she can help you learn how other people have dealt with the same concerns.
Benefits and Drawbacks of Genetic Testing
A genetic test itself is simple, but the decision to have it can be complex. You may be unsure whether you want to know this information—and what you will do with it once you find out.
The main benefit of testing is knowledge. If your relative who has cancer tests positive for a mutation, then you know that the cancer in your family is likely due to heredity. Your test result can tell you whether or not you have the mutation.
- If you test negative for the mutation, you no longer have to worry about being high-risk. Your risk is the same as that of people in the general population.
- If you test positive, you can take some steps to prevent cancer, or try to catch it early if it does develop. For example, some women who have the BRCA1 or BRCA2 mutation choose to have their breasts or ovaries removed. Others have more frequent screening tests, such as mammograms for breast cancer, or take medications found to decrease risk, such as oral contraceptives (birth control pills) for ovarian cancer.
However, there are some potential drawbacks, too.
- You could feel excessively anxious after a positive result. You may not want preventive surgery, and you may worry that screening and medications offer no guarantees against getting cancer. There are no completely foolproof strategies for preventing cancer.
- Testing also can cause family strife if members disagree on whether or not it is a good idea. Those who test negative might feel guilty for being spared the mutation, while those who test positive might feel resentful or angry.
- Genetic testing does not always provide black-and-white information. There are cases in which genetic tests have given "inconclusive" or even incorrect results.
Also, if you do test positive for the mutation that runs in your family, this does not mean you will definitely get cancer—only that your risk is much higher than that of the general population.
If you test negative, this result is meaningful only if the mutation has been confirmed in another relative who has had cancer. If it has not, then you are still considered high-risk, based on your family history. It may be that another yet-to-be-discovered mutation is responsible for the cancer in your family.
Clearly, the issues surrounding genetic testing are complex. It's important to weigh all of them carefully before moving ahead. Your doctor and genetic counselor can help. For more information, see Genetic Testing: Benefits, Limitations, and Keeping Results Private.