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10 Things You Should Know About At-Home Genetic Tests for Cancer

Nowadays, looking into “what makes you, you” takes as little as six weeks. At home DNA tests can provide valuable insight into your risk for certain diseases, including some cancers, but these tests aren’t foolproof, and the results may not tell the full story of how your genes could affect your health.

Michael J. Hall, MD, MS, Interim Chair and Associate Professor in the Department of Clinical Genetics, and Andrea Forman, MS, LCGC, former Senior Genetic Counselor at Fox Chase Cancer Center, shed light on some of the most pressing questions about at-home genetic tests.

1. What is at-home, or direct-to-consumer (DTC), genetic testing?

There are a number of DTC test kits you can order without a doctor’s prescription that offer personalized genetic analyses ranging from ancestry to health risks. The health tests may tell you what your risk for a certain disease is, like cancer or Alzheimer’s. It is important to remember that DTC tests detect genetic markers that may increase disease risk, but being at risk for a disease does not mean you will ever get the disease.

2. Are DTC tests a good place to start for patients concerned about cancer?

“Conducting DTC tests to learn more about your ancestry can provide fun, interesting information,” Hall said. “My concern is with predictive tests for medical issues. It is optimal for patients receiving medical information to have genetic counseling, or at least have a physician oversee the process.”

Forman agreed. “Information from health-based genetic risk tests may or may not have any impact on what medical care you need. Also, how confident can a patient be if test results don’t show any risks? Several other factors, such as lifestyle choices and family history, can also affect disease risk. Genetic test results can bring a mix of emotions about potential health impacts,” she said. “People with a true medical concern and those looking for guidance should meet with a medical professional.”

3. Are there benefits to DTC genetic testing?

DTC tests can raise public awareness about genetic information. Some tests can be ordered in partnership with a doctor and may provide a way for people to get screened even if they live far away from a testing center, cannot afford testing, or get denied coverage for screening because they don’t have a family history of disease, according to Forman.

4. What is the downside of DTC genetic testing?

“We tend to focus on the things we are interested in, that are congruent with our existing beliefs,” Hall said. “If you are unaware of certain risks in your family, you may scan the results, quickly dismissing some while being overly concerned about others. People might see that they have a high lifetime risk of a certain cancer and feel alarmed, whereas if they saw a genetic counselor they would know there are ways to substantially mitigate the risk and potentially never get cancer,” he said.

Forman cautioned about over-interpreting the reams of raw data DTC companies send you. A recent article in Genetics in Medicine found that 40 percent of variants in genes reported in DTC raw data were false positives. Certain common genetic variants were also misclassified as being associated with increased risk. It turns out that DTC testing may involve “spot checking” your results, not the comprehensive analysis done during usual clinical diagnostic testing, she said. Positive results are typically not confirmed with a “double check” test, which is recommended in clinical genetic testing labs.

5. What’s different about going to a genetic counselor instead of taking a DTC genetic test?

“We go through medical and family history to make sure testing is clinically appropriate for the patient,” Forman said. “For some patients, everything looks great and they do not need testing; but patients who have a family history of cancer or have other risk factors get a full assessment,” she said. “I explain the potential benefits and limitations of testing, so patients can make informed decisions.”

Having a risk for cancer on a DTC test does not mean you have or will ever get cancer.

6. What can a genetic counselor do for potential cancer patients?

“We want people to talk to a genetic counselor before and after they get screened, so they know what they are getting into, what the results mean, and what to do next,” Hall said.

Forman added, “One of the big benefits is having somebody be your advocate to make sure you are making decisions for yourself and your family based on good information. I spend an hour or so with my patients, asking questions, giving feedback, and letting them ask questions. Even patients who don’t initially think they need to meet with me tell me how helpful it was and how much better they feel afterwards,” she said. “We are also good at helping with logistics—insurance coverage, which lab to use, and making sure the test they take will provide the right amount of information. It can be time well spent so that you know the ins and outs of something that can have such a big impact on you and your family.”

7. What does Fox Chase offer that does not come with DTC testing for cancer risk?

“There are advantages to coming to Fox Chase rather than doing at-home genetic testing,” Hall said. “For patients who have a genetic risk, we can discuss screening, prevention, and treatment options that may benefit them. We can guide patients who need treatment to new therapeutic targets that may lead to clinical trials,” he said. “We help patients’ family members get screened, if appropriate. We offer family planning for anyone concerned about passing on certain genetic risks to their children. Social services are also available for patients who feel overwhelmed or distressed.”

At Fox Chase, we give people the resources to make the right decisions for themselves.

8. What if you take a DTC genetic test and then have questions?

“If you take a test at home, call our genetic counseling program so someone can walk you through the results,” Hall emphasized. “This is really important to understand if you actually have a risk of cancer. Patients and doctors alike can misinterpret genetic results. My biggest task is to educate people on what the test results mean, and what you should do with the results.

Forman added, “I’d explain that DTC test results need to be confirmed for accuracy at a clinical laboratory that specializes in that genetic test. We want to get all of the information we need before jumping into action.”

9. What if you have already taken a DTC genetic test and are told you have a positive marker for cancer?

“It is very valuable to come to us for follow-up,” Forman encouraged. “We can get into the details of what the results mean, your options for screening, prevention, and what you can do to keep yourself healthy. It is also important to understand that some, but not all, family members may carry the same risk factors. We can give you information to share with your family.”

10. What is all the buzz about DTC testing for BRCA1 and 2 breast cancer gene mutations?

This DTC test addresses only three specific BRCA1/BRCA2 gene mutations out of more than 1,000 known BRCA mutations. Forman said that it is essential to understand that these three mutations are the most common mutations in people of Ashkenazi Jewish descent, but are not the most common BRCA1/BRCA2 mutations in the general population. “It scares me that a woman will take the DTC test, find out she doesn’t have one of these three mutations, and the negative results will falsely reassure her. I am very worried that this could happen.”

“The positive side to this DTC test is that it can raise awareness about BRCA for women and men,” Hall said. “Many people do not realize that BRCA genes are predictive of prostate and other cancers in men. In fact, the national guidelines recommend BRCA testing for metastatic prostate cancer. This expertise differentiates between getting counseling and screening at Fox Chase instead of using a DTC kit.”

If you remember one thing, remember this: Having a risk for cancer doesn’t mean you will ever get it. If you take a test at home, call the Fox Chase Risk Assessment Program to talk to someone who can walk you through the results. If you have concerns about cancer risk, let genetic counselors help.

Find out more about the Risk Assessment Program at Fox Chase.