Genetic Testing Guide
Understanding Test Results And Options
InteliHealth Medical Content
How Do You Make Sense Of The Results?
Although it is "just a blood test" the implications and results of a genetic test are not always black and white. Even for a woman who has survived breast or ovarian cancer, the test may not be as clear as she thinks.
Here are the possible test results:
A positive test result means that you have a mutation in BRCA1 or BRCA2. This means you have an increased risk for cancer. However, the test cannot tell you if or when you will develop cancer or a second cancer. Although the risk is high, some women with these mutated genes never develop cancer during their lifetime.
Although the course of action is not the same for each person who finds out that he or she has a BRCA1 or BRCA2 mutation, the results can influence medical care. For example, most experts agree that intensive cancer screening should start at young ages after a positive test result. Your doctor might also recommend preventive surgery based on the results.
As far as researchers know, there are no true "false positives" without lab error. A "false positive" could happen if two samples were somehow switched either before or after the laboratory received them. It is important to make sure that the laboratory that performs the test is reputable and is certified to perform the test. There should be mechanisms in place to prevent these kinds of errors from occurring at both the testing laboratory and at the hospital. These types of mix-ups are very unusual.
If you are the first person in your family to get tested, a negative test result does not guarantee that you won't get cancer. You could still have a change in the BRCA1 or BRCA2 genes outside of the region tested, or you could have a change in another gene that could lead to cancer.
The current clinical test for BRCA1 and BRCA2 is designed to detect two types of changes in the gene. There could be changes in a single letter of DNA sequence or large missing pieces of the gene also called a "deletion." The lab that does this testing uses a combination of methods to detect both types of changes.
Without a known mutation in the family, a negative result for someone who has not had breast or ovarian cancer can mean several things:
- Your family's cancer history was caused by a BRCA1 or BRCA2 change that you did not inherit; other family members could still be at risk
- Your family's cancer history was caused by a different gene, which you may or may not have inherited. (The test only identifies altered BRCA1 or BRCA2 genes it does not test for every possible cancer-associated gene).
- The cancer in your family was not caused by an inherited gene, but may have a common environmental component (caused by exposure to some toxic substance, for example) or may have occurred by chance.
- The cancer in your family might be due to a change in the BRCA1 or BRCA2 genes that was not detected by the test. The currently available testing cannot guarantee the ability to find all possible changes in these genes.
- Your genetic counselor has no way of knowing which of these possibilities is the right one. A counselor can, however, assess the likelihood of each one of these options by examining your family history. This is why BRCA1/2 testing is only recommended for people whose family history suggests that they have a high chance of carrying an altered BRCA1 or BRCA2 gene.
It is also possible to get a "false negative" result. This means you may have an altered form of one of the genes, but the test did not detect it. As mentioned above, currently available testing cannot guarantee the ability to find all possible changes in these genes.
A variant result is a "maybe" answer. In some cases, the lab will eventually decide that the alteration is important and does increase the risk for cancer. In other cases, the lab may decide that the variant probably won't increase your risk for cancer. At the time that you get your test result, the lab may not know which one is the right answer because you might be the only person to ever have that particular change in the gene. Your genetic counselor can try to help you sort through what a result like this means for you.
Why would I want to know if I had an altered gene?
Knowing that you had an altered gene could:
- Help you to figure out if you are at increased risk for developing breast and ovarian cancer. The annual screening recommendations are different for people with a BRCA1 or BRCA2 mutation.
- Help you to make decisions about preventive surgery or medications.
- Help other family members better understand their risks for cancer.
- Help to explain why you or other family members developed cancer.
- Help you to decide when you need to start to screen for cancer.
- Help you to make decisions about childbearing.
- Motivate you or your family to do self-exams, get screening tests and go to the doctor.
Why would I not want to know if I had an altered gene?
On the other hand, finding out you had an altered gene could:
- Make you anxious or worried.
- Make you feel pressured to make decisions about preventive surgery.
- Make you feel too guilty about the possibility that you could pass (or have passed) the gene on to your children.
- Make you less likely to go to the doctor or get screened because of the fear of what might be found.
- Give your family information that they do not want, causing them to resent you.
- Make it harder for you to get or keep insurance.
How might I react to a positive result?
For some women, finding out about a BRCA1 or BRCA2 mutation can be devastating emotionally. Others feel a sense of relief in knowing what they suspected to be true all along or at finding out a reason for the cancer. Studies have shown that most women learn to adjust well to a positive test result.
Some women choose not to be tested because they are concerned about their reactions. You should ask your genetic counselor about resources for women who are having a hard time coping with results. In some cases, referrals may be made for psychological care with a therapist or mental health professional.
How might I react to a negative result?
For most women, a negative result is good news. However, a negative result can frustrate some women because they were looking for an answer or explanation for their cancer. Also, it may be difficult to feel truly happy about a negative result when another family member has tested positive. If someone in your family has a mutated gene, and you learn you did not inherit the gene, you may feel guilty.
These feelings are normal; your genetic counselor can discuss them with you and provide support. If these feelings become overwhelming, it may be useful to speak with a mental health professional.
How might I react to an inconclusive result?
Inconclusive results (called "variant" results) can be the most frustrating results to receive. When the mutation has never been seen before or there is little information that the laboratory can give you about it, you may find the uncertainty difficult to cope with.
In the long run, most inconclusive results are changed to negative. However, in a few cases, the result will be considered positive. In either case, the laboratory will contact your genetic counselor or physician and update them as soon as it is confident of the interpretation. This may take months or years; in the meantime, you may be in limbo about what this means for you and your family. Genetic counselors understand that living with uncertainty after going through the process of genetic testing can be emotionally draining. If you feel that you are not coping well with this type of news, ask your genetic counselor about finding a mental health professional.
How will my results affect my family members?
Genetic testing is often a family affair. Your family history often determines whether you should have a genetic test. It is hard to get this kind of background information without discussing it with your family members. That's why it is recommended that you discuss genetic testing as a family, so you will know how other family members feel about your pursuit of this information and genetic testing in general.
Should I share my results with my family?
Your results may give other family members the opportunity to learn more about their risks for cancer or provide reassurance. However, you generally have no legal obligation to share genetic information that you learn through your own testing.
Screening And Prevention
What screenings are recommended for me if I had a BRCA1 or BRCA2 mutation?
You should discuss the management of cancer-risk screening and prevention with a doctor who is familiar with these issues and can provide you with information about research studies for which you may be eligible.
The National Comprehensive Cancer Network published updated recommendations for breast-cancer screening in 2006. The following are recommendations for a woman with a BRCA1 or BRCA2 mutation:
- Monthly breast self-exams beginning at age 18.
- Breast exams by your doctor or nurse every 6 months beginning at age 25.
- Annual mammogram and MRI beginning at age 25.
Magnetic resonance imaging (MRI) and ultrasound are newer types of screening tools. Many experts recommend yearly MRI exams, but breast MRI is not available everywhere. Researchers are still trying to figure out how often to perform mammogram and MRI exams to provide the best care to patients. There are also new techniques that are on the cutting-edge of research, like ductal lavage. The value of these tests in women who have an altered gene is not known; research studies are under way.
Ovarian-cancer screening is more controversial because it has not been proven to detect cancer at an earlier, more curable stage. At this point, the most common recommendation is to consider having your ovaries removed around age 35-40 or after you are finished having children. If a woman chooses not to do this or still wants to have children, the most common suggested screening is to begin receiving transvaginal ultrasounds every six months beginning at age 30.
Your doctor may also suggest a blood test once or twice a year to check for levels of a protein called CA-125. Increased CA-125 levels are associated with normal periods, benign conditions, and, sometimes, gynecological cancer. (In general, however, CA-125 testing is not recommended until after menopause because levels of the protein can fluctuate with menstrual cycles.)
Researchers are studying ways to detect ovarian cancer at earlier stages. Women who are at increased risk would be eligible for these studies.
All women 18 and older (and younger women if they are sexually active) should have an annual gynecological (internal) exam, including a Pap test, which is a screening for cervical cancer.
What preventive measures can I take if my test suggests an increased chance of getting breast or ovarian cancer?
You may be presented with several different options if you find out that you have an altered gene.
This is the removal of the ovaries as a preventive measure. Because early-stage ovarian cancer is hard to detect, most experts recommend removing a woman's ovaries around age 35 to 40 or when she is through having children. This surgery decreases the risk of ovarian cancer by about 90 percent. Removal of the ovaries may also reduce breast-cancer risk in women with an altered BRCA1 or BRCA2 gene by as much as 50 percent.
Even if both ovaries are removed, you will still have a chance of developing ovarian cancer. Cells in part of your abdomen, called the peritoneum (which is the bag that holds the abdominal organs), look and act like ovarian cells. It is possible that cancer could still develop in these cells.
This is the removal of healthy breast tissue as a preventive measure. Some women choose to have their breasts removed to reduce their breast-cancer risk as much as possible. This type of surgery is thought to reduce the risk of a new breast cancer by up to 90 percent. Not all breast cells can be removed by this procedure, so there is a chance that cancer still can develop.
This surgery is complicated and requires in-depth discussions with a breast surgeon as well as a plastic surgeon and often a mental health professional. After this surgery, a woman does not have to undergo mammograms or other breast imaging. Clinical exams may still be performed.
The issues surrounding the removal of healthy tissue to prevent the possibility of cancer are complex. Each woman will have a different opinion about the surgery and the level of risk she can live with. Discuss these issues with your health-care team so you make a fully informed decision.
Tamoxifen is a drug that was first used to treat breast-cancer patients. It works best for treating and preventing estrogen-receptor positive breast cancer because the drug is an "anti-estrogen." It has also been shown to reduce breast-cancer risk by about 50 percent in healthy women. Raloxifene is a selective estrogen receptor modifier (SERM), another type of "anti-estrogen." Results of the STAR Trial (Study of Tamoxifen and Raloxifene) were published in June 2006. In the STAR trial, Tamoxifen and Raloxifene showed a similar ability to reduce breast cancer risk. It is not clear at this time whether either drug is effective for reducing breast-cancer risk in women with an altered BRCA1 or BRCA2 gene. Serious side effects can occur with either drug, and these should be discussed with your doctor.
Other drugs, such as aromatase inhibitors, are still being studied for their effects on breast cancer prevention. Exercise caution when you consider any of these chemopreventive drugs.
What kinds of screening are recommended if I do not have a BRCA1 or BRCA2 mutation?
Screening depends on your medical history and that of your family. Some women need to be followed closely; others may need less intensive monitoring. Talk to your doctor about the right screening for you.
Who does the BRCA1/BRCA2 test?
Myriad Genetic Laboratories in Salt Lake City, Utah is currently the only laboratory in the country that does the test because they have the patent on the genes. They have three types of tests. One is called "comprehensive" and is the most expensive. The second test is called "single site" because it only looks at one part of the gene for example, if you already know which change runs in your family, they only look for that one. The third test only looks at a few changes in the gene that are common in people with an Ashkenazi Jewish background. You might be able to get the less expensive test if you are just looking to see if you have the same mutation as a family member.
What is the cost of the test?
The cost of the test depends on what type of test is being done. The most complete test is the most expensive, costing nearly $2,800. Targeted tests cost much less, in the range of a few hundred dollars.
Does insurance pay for the test?
Most health insurance companies will pay 80 percent or more of the cost of the test. Some companies pay all of the cost, but others won't pay any portion. If you are considering this test, call your insurance company and ask about its coverage.
How long does it take to get results?
It takes about three weeks to a month to get results when the lab is doing the full-gene testing. Targeted testing takes anywhere from two to three weeks.
Can a health insurance company raise my rates or drop me from coverage if I test positive?
Not usually, though this may depend on whether or not you have group insurance or are self-employed. People with group insurance are usually covered by both federal and state laws, while people who are self-employed are only covered by state laws. Also, the Federal Health Insurance Portability and Accountability Act (HIPAA) of 1996 prohibits health insurance discrimination based on any "health status-related factor," (including genetic information) by group health plans. Unfortunately, this act does not apply to the self-employed.
Some states have enacted legislation to cover the gaps. Thirty-four states prohibit health insurance companies from using genetic information to deny coverage. Other states require specific justification for the use of genetic information in denying a claim. Texas bans the use of genetic information by any group health plans, and Alabama prohibits discrimination based upon predisposition to cancer.
Life insurance, long-term care and disability insurance are generally not covered by these laws. People with life and disability coverage provided by their employers are unlikely to have this insurance affected by a genetic test result.
For information about laws in individual states, click on the following links.
Learn more about life insurance, disability insurance, and long-term care insurance laws.
Learn more about health insurance laws.
Last updated July 10, 2006
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