Update: FDA approves at-home test kits for inherited cancer: how useful are they?
|Direct-to-consumer testing||What does this mean for me?|
|Risks of DTC testing||Guidelines|
|Benefits of test||Resources|
|Testing without healthcare professionals|
With direct-to-consumer genetic testing, a person can order their own test directly from the laboratory, with no doctor involved. In the past, testing for inherited mutations that raise the risk for disease has required a doctor's prescription. The recently approved the first direct-to-consumer (DTC) test that looks for three mutations in the and genes. These mutations have been linked to increased risk for breast, ovarian, pancreatic, and other cancers. This new approval allows people to order a kit, collect a saliva sample, send it directly to the 23andMe lab for testing, and receive their genetic results without involving a doctor.
- The 23andMe test is an incomplete test for cancer risk.
- The test only looks for 3 out of over 1000 possible mutations in genes ( 185delAG, 5382insC or 6174delT). These three mutations are found most commonly in people of Ashkenazi (Eastern European) Jewish descent. For people who test positive for a mutation, the 23andMe test provides important information about their risk for cancer. But for people who test negative, the test does not provide much information about cancer risk.
- The approval statement notes that 1,000 other mutations also increase cancer risk. Technically, this is accurate, but it is a dramatic understatement. To date, over 5,400 different mutations (2,549 in and 2,941 in ) that can increase cancer risk have been identified.
- Over 25 other genes have been linked to increased risk for hereditary breast, ovarian and other cancers. Mutations in other genes, such as , and and others also increase cancer risk. So, a person whose 23andMe test is negative for a mutation may still have a different mutation in or or another gene that significantly increases cancer risk.
- The report fails to mention that more complete tests are available to help people understand their cancer risk. Tests are available that look for the thousands of other mutations as well as mutations in other genes which are not detected by the 23andMe test. The cost for these tests are often covered by insurance and low-cost options may be available.
- Individuals who receive a negative test result from 23andMe may have a false sense of confidence about their cancer risk. As the cautions: “The test should not be used as a substitute for seeing your doctor for cancer screenings or counseling on genetic and lifestyle factors that can increase or decrease cancer risk.”
- Leading experts set guidelines for cancer care, working through an organization known as the National Comprehensive Cancer Network (NCCN). NCCN recommends that people consult with a genetics professional before and after genetic testing. By sidestepping the need for a prescription, DTC genetic testing falls below standard-of-care.
People of descent who have never had testing will have the most benefit from the 23andMe test. About 2% of all people—regardless of personal or family history of cancer—will carry one of the 3 mutations in the 23andMe test.
However, even people can have a mutation in one of the over 5,000 other mutations, or in another gene like , or . One study showed that among Jewish women with breast cancer, 0.8% have other mutations and 3 to 4% carry a mutation in another breast cancer gene (see our prior XRAY Does expanded genetic testing benefit Jewish women diagnosed with breast cancer?) These mutations are not detected in the 23andMe test. Therefore, negative results among individuals are not conclusive either.
This new 23andMe DTC test has very limited usefulness for the general population. The test may benefit those who are unaware of their Jewish ethnicity and who test positive for one of the 3 mutations.
In DTC testing no medical or genetic counseling is included. Test results are returned electronically with a written explanation. Further questions and discussion of follow-up testing or treatment options are not included. As the notes, this test should not be used to make health care decisions: “Consumers and health care professionals should not use the test results to determine any treatments, including anti-hormone therapies and prophylactic removal of the breasts or ovaries. Such decisions require confirmatory testing and genetic counseling. The test also does not provide information on a person’s overall risk of developing any type of cancer. The use of the test carries significant risks if individuals use the test results without consulting a physician or genetic counselor.”
The examined how the test is performed and assures people that the test is accurate and reliable. The agency also warns that people should understand what this test does and does not tell them. They caution that without an expert explaining the meaning of the test results, misunderstandings may occur. Many genetics experts agree and believe that genetic testing for health information is best done in the clinical setting in consultation with medical professionals.
In their approval, the make the following notes about test results through 23andMe:
- Consumers and health care professionals should not use the test results to determine any treatments, including anti-hormone therapies and prophylactic removal of the breasts or ovaries. Such decisions require confirmatory testing and genetic counseling.
- The test also does not provide information on a person’s overall risk of developing any type of cancer. The use of the test carries significant risks if individuals use the test results without consulting a physician or genetic counselor.
- The test only detects three out of more than 1,000 known mutations (the three most common in people of ancestry). This means a negative result does not rule out the possibility that an individual carries other mutations that increase cancer risk. All individuals, whether they are of descent or not, may have other mutations in or genes, or other cancer-related gene mutations that are not detected by this test. For this reason, a negative test result could still mean that a person has an increased risk of cancer due to gene mutations.
The 23andMe test can check your for three specific mutations. Negative results provide very limited information, and are likely to be confusing to a person who undergoes testing without speaking to a genetics expert. Even if you are of decent, you may have a mutation in , 2 or other genes that are not included in this test.
Positive results may provide valuable information about risk for certain cancers, and options for manging these risks. However, because this testing is done without medical oversight, people should be aware of these important considerations:
- Your health care provider will be aware of your result only if you share them.
- People with a positive results might have to pay additional costs (dependent on individual insurance coverage) for a second test to confirm the results of their 23andMe test. People who have testing with 23andMe should consult with a genetic counselor to understand their results. 23andMe does not provide follow-up testing.
- For most consumers, the actual benefit of this test will be through follow-up genetic counseling and follow-up visits with doctors.
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U.S. Food and Drug Administration. authorizes, with special controls, direct-to-consumer test that reports three mutations in the breast cancer. Published March 6, 2018.
National Comprehensive Cancer Network. Genetic/Familial High-Risk Assessment: Breast and Ovarian.
FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.
This article is relevant for:
People who are considering or have had direct-to-consumer testing through 23andMe
This article is also relevant for:
Breast cancer survivors
Healthy people with average cancer risk
Men with breast cancer
Ovarian cancer survivors
Triple negative breast cancer
Women under 45
Women over 45
Be part of XRAY:
After this report was published by the , a large number of media sources covered it. This includes NBC News which published “ OKs 23andMe home breast cancer test, with warning," containing a misleading graphic. FORCE covered the article in a recent Headline Hype blog post.
This direct-to-consumer test is a reliable way to identify 3 specific
mutations. Individuals who test negative may carry one of thousands of other mutations in or 2 or in a breast cancer gene that is not included in this test. Consumers may underestimate their risk of breast cancer and other cancers associated with these mutations, including ovarian cancer in women and cancer in men.
For additional information read FORCE advisor board member and 2018 Spirit of Empowerment awardee Dr. Susan Domchek’s piece "At-home genetic testing may be convenient, but it isn’t complete" in Stat News.
Share your thoughts on this XRAYS article by taking our brief survey
NCCN guidelines recommend genetic counseling and testing for people without cancer who have the following family history:
- A relative who has tested positive for an inherited mutation in a gene that increases cancer risk.
- One or more first- or second-degree relatives with breast cancer and any of the following:
- diagnosed at age 45 or younger
- two separate breast cancers, with the first diagnosis at age 50 or younger
- male breast cancer
- One or more first- or second-degree relatives with:
- colorectal cancer before age 50
- endometrial cancer before age 50
- ovarian, , primary peritoneal cancer
- rare or childhood cancers
- One or more first-degree relatives with:
- or high-grade cancer
- pancreatic cancer
- Two or more relatives on the same side of the family diagnosed with any combination of the following at any age:
- breast cancer
- pancreatic cancer
- adrenal cancer
- brain tumors
- endometrial cancer
- thyroid cancer
- kidney cancer
- diffuse gastric cancer
- colon cancer
- Given my personal and family history, will this test be informative?
- Are there other options for genetic testing? How do they compare to this test?
- If I test negative, should I consider further genetic testing?
- If I test positive, what is my cancer risk? What preventative measures could I consider? Should I consider different treatment options?
- Should I share my 23andMe results with my relatives? Which ones?
- Can you refer me to a genetic counselor?
Below are clinical trials that include genetic counseling and testing.
- NCT02665195: Registry Of MultiPlex Testing (PROMPT). PROMPT is an online research registry. The goal of PROMPT is to help researchers to better understand the risks that are linked to mutations in less well-studied genes.
- NCT04245176: Genetic Testing for All Breast Cancer Patients (GET FACTS). This study looks at the impact of a novel genetic counseling method on surgical decisions in people with newly diagnosed breast cancer. This study involves genetic counseling about risk.
- NCT02620852: WISDOM Study: Women Informed to Screen Depending on Measures of Risk offers women age 40-74 the opportunity to undergo risk assessment and genetic testing in order to determine the best breast screening options based on their situation.
- Enhancing Genetic Risk Assessment in Underserved Blacks and Latinas at Risk of Hereditary Breast Cancer. This study will test how well educational materials increase the use of knowledge about risk.
- NCT04476654: Improving Uptake of Genetic Cancer Risk Assessment in African American Women-Video. This study looks at the usefulness of intervention with a culturally-tailored video to improve uptake of genetic counseling in Black women who are at increased risk of .
Other genetic counseling or testing studies may be found here.
FORCE offers many peer support programs for people with inherited mutations.
- Our Message Boards allow people to connect with others who share their situation. Once registered, you can post on the Diagnosed With Cancer board to connect with other people who have been diagnosed.
- Our Peer Navigation Program will match you with a volunteer who shares your mutation and situation.
- Our moderated, private Facebook group allows you to connect with other community members 24/7.
- Check out our virtual and in-person support meeting calendar.
- Join one of our Zoom community group meetings.
Health care providers who are specially trained in genetics can help you more clearly understand your risk for . The following resources can help you locate a genetics expert in your area.
- The National Society of Genetic Counselor website offers a searchable directory for finding a genetic counselor by state and specialty. To find a genetic counselor who specializes in cancer genetics, choose "cancer" under the options "Area of Practice/Specialization."
- InformedDNA is a network of board-certified genetic counselors providing this service by telephone. They can also help you find a qualified expert in your area for face-to-face genetic counseling if that is your preference.
- JScreen is a national program based out of Emory University that provides low-cost at-home genetic counseling and testing with financial assistance available.
- Grey Genetics provides access to genetic counselors who offer genetic counseling by telephone.
- The Genetic Support Foundation offers genetic counseling with board-certified genetic counselors.
- FORCE's toll-free helpline at: 866-288-RISK, ext. 704 will connect you with a volunteer board-certified genetic counselor who can answer general questions about genetic testing and cancer and help you find a genetics expert near you.
- FORCE Peer Navigator Program will match you with a volunteer who has undergone genetic counseling and can help you navigate resources to find a genetic counselor near you.
- Ask your doctor for a referral to a genetics expert.
Who covered this study?
Oncology community sees potential for patient harm in FDA ok of 23andMe BRCA test This article rates 5.0 out of 5 stars
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23andMe gets FDA approval for at-home breast cancer risk test This article rates 2.5 out of 5 stars