Best Genetic (DNA) Tests For Cancer Risk

Updated August 8, 2019

This article was scientifically reviewed by Jessica Bucher

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A list of references is also included at the bottom of this article.

According to research by the American Association for Cancer Research, the average American is afraid of developing cancer at some point during their life. In fact, a survey of more than 1,000 voters showed that nearly 75 percent of people know someone who has died from cancer.

What's in this Guide?

Disclaimer: Before You Read

It is important to know that your genes are not your destiny. There are various environmental and genetic factors working together to shape you. No matter your genetic makeup, maintain ideal blood pressure and glucose levels, avoid harmful alcohol intake, exercise regularly, get regular sleep. And for goodness sake, don't smoke.

Genetics is a quickly changing topic.

Even further, nearly 50 percent of people said that they were more afraid of developing cancer within their lifetime as opposed to any other illness, and that they were more afraid of being diagnosed with cancer than being the victim of a violent crime or a national emergency.

This fear of cancer has led many people to consider having genetic testing, specifically to determine their chances of developing cancer. And, as genetic testing becomes more affordable and accessible to people across the country (and the world), there’s a lot to know about what this kind of testing can tell you.

If you’ve ever thought about having a DNA test for cancer performed, but have questions, keep reading to learn more.

Can Genetic Testing Detect Cancer?

Genetic testing for cancer and other health conditions goes by several names, including predictive genetic testing (or presymptomatic testing).

That’s simply because these tests can examine your DNA to determine your future risk of developing disease or health conditions.

When it comes to answering the question of whether genetic testing can detect cancer, you should understand that presymptomatic genetic tests cannot definitively tell you whether or not you will get cancer. As more and more people are able to access genetic testing, many are taking DNA tests to evaluate their risk.

But some of these people don’t realize that no test can rule in or out that you for sure will or won’t get any disease. In addition, you should know that a genetic test for cancer can’t tell you if you currently have or previously had cancer or another disease.

So, if a DNA test can’t give you a 100 percent guarantee that you will or won’t get cancer (or another disease), should you still consider taking the test?

Depending on your personal and family history, cancer researchers and health care professionals say yes, and that predictive genetic testing — that is, genetic or DNA testing for understanding your cancer risk — has the ability to provide you with an accurate idea of just what risk level you carry for developing a genetic form of cancer 1.

According to research by James Evans, the director of cancer genetics services at the Lineberger Comprehensive Cancer Center, you should know these things about genetic testing for cancer and other health issues:

  • Most of the predictive genetic tests have some level of uncertainty about the fine details related to potentially developing a disease — including whether you will definitively get the disease, at what point in your life you will be diagnosed, and how severe the illness may be. That means a genetic test for cancer or another health condition won’t give you this kind of information — and that’s because no test truly can.
  • For people looking into genetic testing for conditions such as cancer, the knowledge gained from having the test done all depends on the treatment options available, and that testing should be personalized to meet each person’s health needs. For example, people who are worried about developing breast cancer due to family history may make different preventative health choices if they test positive for carrying a BRCA gene than someone who does not. For cancers and health conditions that have few or no treatment options, knowing whether you’re at high risk for inheriting a disease can be stressful and may not offer you any solutions.

So, when it comes to asking yourself if you should take a test to determine your cancer risk, you may want to keep these points in mind.

Just like any genetic or DNA testing, the kind of information you want to know about your personal health — and how you plan to use that information — are important factors when it comes to taking one of these predictive tests.

It’s also important to think about how this information might benefit others in your family. For example, if you test positive for a genetic mutation in a gene that increases cancer risk, your close family members may or may not want information about this.

How Does Genetic (DNA) Testing For Cancer Work?

In general, genetic testing (or DNA testing) uses a sample of your DNA, obtained through either saliva or blood, to look for specific genetic mutations.

These mutations can be present in a person’s genes (the components of DNA that are passed onto you from your mother or father) which are held on structures called chromosomes.

After obtaining your DNA sample, a genetic scientist will digitize your DNA and observe it on a computer, looking at the portions of your genetic code that may have changes, or mutations.

Because cancer research has made huge strides in the last 50 years, genetic scientists and researchers are able to identify specific gene mutations that increase your risk of developing certain kinds of cancer.

By observing whether or not these mutations are present, a DNA test can help you understand your personal level of cancer risk for cancers that are related to genetics.

There are two main ways you can have genetic testing performed: through your doctor or genetic counselor’s office, or through an at-home DNA testing kit.

What Is A BRCA Test?

Many people have heard about genes that put you at higher risk of developing breast cancer.

The most commonly known genes are called BRCA genes — short for (br)east (ca)ncer. These genes don’t actually cause cancer, and researchers know that they actually help to prevent cancer by repairing broken chains of DNA that can lead to the development of cancer.

But, sometimes these BRCA genes have mutations and go haywire, meaning that they can lead to increased risk for some forms of cancer.

There are two forms of mutated BRCA genes that researchers know are linked to cancer: BRCA1 and BRCA2 2.

BRCA tests are a form of genetic testing that examine your DNA and determine if a BRCA1 or BRCA2 mutation is present. If it is, your risk of developing breast cancer increases 3.

But, having a BRCA genetic test performed, and having it show that a BRCA1 or BRCA2 gene mutation is present doesn’t mean that you have breast cancer, or will get breast cancer. Instead, it just shows that your risk is higher, and gives you options to reduce your chances of developing breast cancer.

This may include increased screening, medications, and preventative surgeries. Since mutations in these genes can also cause other types of cancer, it can also help you make decisions to prevent those cancers as well.

Research has come a long way to determine that there are many more genes associated with a higher risk of breast cancer. Therefore, your doctor or genetic counselor may recommend having a genetic test for mutations in BRCA1, BRCA2, as well as many other genes on a “panel”.

Who Should Get Genetic Testing For Cancer Risk?

Cancer researchers know that only a small amount of cancer cases are related to genetics — in fact, only about 5 to 10 percent.

In most cases of cancer, lifestyle choices and environmental factors — such as having a poor diet, smoking, or working at a job that has regular exposure to carcinogens — are the leading causes of cancer development 4.

So does this mean that genetic testing for determining your cancer risk isn’t worth the effort or money? Not necessarily. Many oncologists and cancer specialists in the medical field believe that genetic (DNA) testing for determining the chances of developing cancer can be beneficial for people who may have some elevated risk.

According to the MD Anderson Cancer Center at the University of Texas, genetic testing can be a useful health and medical decision-making tool for people who are at higher risk of developing cancers because of their family’s health history.

But when it comes to determining if you’re at a higher risk of developing cancer, it can be tricky. How do you know if you should consider taking a cancer risk test?

The American Cancer Society has several recommendations that may help you identify whether or not you could be a high-risk individual.

According to the American Cancer Society, you may want to consider genetic testing for cancer if:

  1. You have several close relatives who have been diagnosed with cancer — such as a parent, sibling, or child
  2. You know of many relatives on your mother or father’s side of the family who have had the same type of cancer
  3. You have a family member who has been diagnosed with multiple types of cancer
  4. People in your family have had cancer at an age much younger than normal for that specific kind of cancer

Because testing for breast cancer genes — also known as BRCA genes — has been a prominent use of genetic cancer testing, you may be wondering if there are additional guidelines specific to breast cancer testing.

According to the Susan G. Komen Breast Cancer Foundation, undergoing a genetic test to determine your risk for cancers, such as breast cancer, is only recommended for people who may be at high risk.

Because most forms of breast cancer are not related to BRCA genes, these tests may not give you a definitive understanding of whether or not you are at certain levels of risk for developing a form of breast cancer.

Still, the National Comprehensive Cancer Network suggests that you may want to consider testing if your risk is increased for reasons such as:

  • You have had breast cancer at or before age 50
  • You have previously had a primary breast cancer in both breasts (called bilateral breast cancer)
  • You have previously had triple negative breast cancer at or before age 60
  • You have had breast cancer at any age, and you have had one or more close blood relatives with:
    1.  Breast cancer diagnosed before or at 50, 
    2.  Invasive ovarian cancer 
    3.  Male breast cancer 
    4.  Pancreatic cancer 
    5.  High grade or metastatic prostate cancer
    6.  Or two or more close blood relatives with breast cancer at any age.

In addition, other people who have a family health history of cancer diagnoses may also benefit from genetic testing for cancer. This might include you, if:

  1. A close relative, such as a mother, sister, aunt, or grandmother, developed breast cancer at or before age 45
  2. You have a family history of ovarian cancer, metastatic or aggressive prostate cancer, or pancreatic cancer
  3. A close male relative, such as a father, brother, uncle, or grandfather, was diagnosed with male breast cancer
  4. A close relative was diagnosed with two or more primary breast cancers
  5. Two or more close relatives were diagnosed with primary breast cancers and one was at or before the age of 50.
  6.  Three or more cancers of other kinds were diagnosed on the same side of the family, especially diagnosed at or before the age of 50.

Further, there are some ethnic groups that may be at higher risk of developing (or redeveloping) cancer. The Susan G Komen Foundation recommends that people who have Ashkenazi Jewish heritage 5 and previous experience with breast cancer 6 consider having genetic (DNA) testing for cancer to fully understand their potential risks.

Where Do I Go For Genetic Testing For Cancer? Can You Do A Genetic Test For Cancer Risk At Home?

If you’re interested in having a genetic test for cancer performed, there are two routes you can take: a doctor’s office DNA test or an at-home DNA test.

Both tests can give you an understanding of your risk of developing cancer.

If your doctor believes you may be at a higher risk of developing cancer based on your personal and family health history, they may order a genetic test for cancer. This test uses blood or saliva to collect your DNA, and in some cases, may be partially covered by insurance (depending on your specific insurance provider).

In a doctor or genetic counselor’s office, collecting your sample take less than five minutes before being sent off to a genetics lab for analysis. Results are often returned to you within two to four weeks.

One downside to DNA tests administered by your doctor or genetic counselor is cost (ranging anywhere from $300 to $5,000), though the one-on-one walkthrough your doctor or genetic counselor provides to explain the pre-test counseling and results is a huge benefit that can be comforting.

The doctor or genetic counselor will take information on your personal history and family history, which can be helpful in ordering the most relevant, thorough test for you. An explanation of what results may mean can also be helpful to help in the decision making process.

If your doctor doesn’t believe you have a high risk of developing cancer based on your personal or family history, an at-home DNA test for cancer is an option. These tests, provided by companies such as 23andMe and Color, use saliva samples to collect your DNA and can be purchased online or in some stores.

After mailing your DNA sample to the company’s laboratory, you can receive results anywhere from two to eight weeks later. One benefit of at-home DNA tests for cancer is that they’re relatively inexpensive, often ranging from $100 to $300.

What Are The Best Genetic/DNA Tests For Cancer Risk?

It is best to discuss the “best” genetic test for you with your doctor or genetic counselor. If you are considering taking at-home genetic/DNA test to determine your cancer risk, know there are several options available to you. Three of the DNA tests available to consumers include:

  • 23andMe: 23andMe’s DNA test is popular among women interested in knowing their breast cancer risk. The company’s test is the first and only FDA-approved at-home DNA test that can test for three specific variants in the BRCA gene. In addition, 23andMe’s can also determine risk for cancers related to those specific variants in the BRCA genes, including prostate cancer and ovarian cancer. However, it is important to note that this testing is not to be used for information on medical management and results need to be confirmed by a clinical grade genetic test. A physician or genetic counselor is not typically involved in the ordering of this testing. There are thousands of mutations in the BRCA genes, and this test looks for only three that are most common in the Ashkenazi Jewish population. 23andMe’s test costs $199.
  • Color: Color’s Hereditary Cancer Test can help you understand your risk for developing genetic forms of cancers, such as ovarian cancer, colorectal cancer, prostate cancer, and more. The test, which costs $199, examines 30 genes including BRCA genes. This testing offers the option to have your own healthcare provider order this testing for you, or you can opt for a third-party physician to be involved in ordering your testing. Either way, a physician or genetic counselor is involved in the process. Results can also be discussed with their genetic counseling team.
  • Invitae:  Invitae’s Proactive Cancer Screen analyzes 61 genes associated with a wide range of hereditary cancers including BRCA genes. The testing offers the option to have your own healthcare provider or a third party healthcare provider to be involved in ordering your testing. Either way, a physician or genetic counselor is involved in the process. Results can also be discussed with their genetic counseling team. The test costs $250.

If you pursue an at-home DNA test and find out that a mutation was identified, it is recommended that you speak to a genetic counselor or doctor about this before pursuing any changes in your medical management.

If you order a test like 23andMe’s test without physician or genetic counselor involvement, it is important to know that this information is not sufficient or accurate enough to make medical decisions or changes in treatment.

Not all genetic tests are created equal, meaning the technology of the tests are not equal. Ordering a genetic test through your doctor or genetic counselor’s office provides many options from different reputable companies.

How Accurate Is Genetic Testing For Cancer Risk?

It’s hard to pinpoint just how accurate genetic testing for cancer is. That’s because these predictive tests can only tell you if you have certain kinds of gene mutations that researchers know are related to cancer development.

When it comes to defining accuracy, most tests are very accurate at telling you whether a particular gene mutation that is tested for (that is linked to cancer) is present or not present 7. But, whether or not those mutations are present in your DNA doesn’t mean that you’ll never get cancer, or that you will definitely get it.

In fact, according to the Susan G. Komen Breast Cancer Foundation, the vast majority of people, primarily women, who develop breast cancer do not have gene mutations (in the BRCA genes or other breast cancer related genes).

The foundation says that within the United States, “5 to 10 percent of breast cancers are linked to an inherited gene mutation,” and that at least half of those identified cancers are specifically linked to BRCA1 or BRCA2 gene mutations.

There is no test that can accurately tell you for certain whether or not you will get any form of cancer.

It’s just not possible to predict the future. But, the information you get back from a genetic test is likely highly accurate if you chose to use a reputable DNA testing source — and how you choose to use that information to analyze your risk and improve your lifestyle to reduce the chances of being diagnosed with cancer is still very beneficial.

How Much Does Genetic (DNA) Testing For Cancer Cost?

People who are considering having a genetic test to identify BRCA genes or other mutations related to cancer often wonder how much a test will set them back.

Because there are many factors at play when it comes to determining the cost of genetic testing, it’s hard to give a specific amount. People who are considering taking a DNA test through their health professional’s office can expect testing to range anywhere from $300 to $5,000.

If, instead, you are not high risk and you choose to go with an at-home DNA testing kit, prices vary by company; at-home kits are much less expensive, often ranging in price from $100 to $300.  However, it is important to remember that this testing may not be appropriate for you based on your personal or family history.

Does Insurance Cover Genetic Testing For Cancer? Does Medicaid Cover Genetic Testing For Cancer?

If you’re looking for help with covering the cost of a genetic test that identifies BRCA genes or evaluates your genetic risk for developing a form of cancer, it may be a setback to know that in most cases, insurance providers do not offer coverage for genetic testing kits that can be taken at home.

Whether you have a private insurance company or have health care coverage through Medicaid or Medicare, these tests are often only covered if performed at a doctor’s office or if your doctor specifically recommends that you take a test.

If you and your doctor or genetic counselor believe that you are at high-risk for developing breast cancer or a hereditary cancer, it may be possible to get your insurance provider (both private and Medicaid) to cover DNA testing if you meet certain eligibility requirements.

However, in most regions, state laws do not require insurance companies to cover the cost of DNA testing, so before you decide to have genetic testing done, you should speak with your health insurance provider to determine what level of coverage you can expect.

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    Mary-Claire King, Joan H. Marks, Jessica B. Mandell, The New York Breast Cancer Study Group. 24 Oct 2003.
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