While you can’t “catch” cancer from a loved one like a virus or an infection, it is a disease that often runs in families.
Genetic testing can gauge your risk of developing cancer — breast, ovarian, colon and pancreatic cancers among them — and help you to be proactive about this risk. Genetic testing can also help physicians choose the best treatment plan if an individual develops cancer. Genetic counseling can coordinate this testing and help you decide what to do if you have an inherited gene mutation that puts you at high risk for cancer.
"We want to be proactive about cancer risks and integrate genetic information into cancer treatment," said genetic counselor Christopher Spencer of Novant Health Cancer Institute - Forsyth in Winston-Salem. "Most of the time we do this testing, and it's reassuring. But it is important when we identify a risk to use that information."
With the science getting more sophisticated by the day, Spencer and his colleague Megan Mayers break down the basics.
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How genes affect cancer risk
Simply put, cancer is caused by changes, or mutations, in genes controlling how cells grow and multiply, according to the National Cancer Institute.
People have two copies of every gene, including ones designed to protect against cancer. A mutation in one copy of a protective gene leaves a person with half the normal cancer protection — and a greater risk. Cancers due to this type of genetic mutation are called “hereditary cancer,” because these mutations are typically passed through multiple generations in a family. There are many different genes related to hereditary cancer that each cause different patterns of cancer risks.
Of note, most cancers are NOT due to an inherited genetic mutation. The majority of cancers are due to random chance and lifestyle factors, rather than genetics. Only 5% to 10% of cancers are thought to be due to inherited genetic mutations. Specific risk factors help to determine who should consider genetic testing.
Why get tested?
If cancer runs in your family, your own risk may rise significantly. Consider seeking genetic counseling if you have any of the following risk factors for hereditary cancer:
- Several family members have had the same type of cancer or have had related cancers — for example, breast and ovarian cancers.
- You or a relative was diagnosed with cancer before the age of 50.
- You or a close relative was diagnosed with a type of cancer that has a higher rate of being hereditary, such as pancreatic, metastatic prostate, male breast or ovarian cancer.
- You or a relative has a history of more than 10 colon polyps.
- You or a relative was diagnosed with a cancer with specific features such as triple negative breast cancer.
- You have Ashkenazi Jewish ancestry, which increases the risk for a mutation in the BRCA1 and BRCA2 genes – genes that produce proteins that help repair damaged DNA.
How genetic testing works
Most often, patients give a blood sample (though sometimes a saliva or skin test is done). Novant Health looks at anywhere from nine to 84 genes — and the number lab scientists can analyze is growing all the time, Mayers said. Expect a three- to six-week wait for results.
"It's a much longer process than a standard blood test," she said. "The lab will extract DNA and test it and look for mutations, but the actual analysis and interpretation of the data is typically the longest part."
How you get your results is up to you: Your genetic counselor can call you to explain the findings, or you can read them in MyChart and follow up with questions later. In most cases, an in-person visit for results isn't necessary.
Explore Genetic Testing
The most common way patients connect with a genetic counselor is through their doctor. That said, you may not need a referral, but genetic counseling appointments are often booked several months in advance. You can contact the Novant Health Cancer Institute genetic counseling office at the following numbers to schedule an appointment:
Winston Salem: Derrick L. Davis Cancer Institute Genetic Counseling 336-277-6000.
Charlotte: Novant Health Cancer Institute – Elizabeth (Cancer Risk and Genetics) 980-302-6270.
Coastal Region: New Hanover Cancer Institute Genetics 910-667-4972.
If you have cancer or specific risk factors, insurance will typically provide coverage of the genetic testing costs. There is a $250 self-pay price through the laboratory for individuals who do not meet criteria for genetic testing, as well as for those whose insurance does not cover the genetic testing. This makes genetic testing much more accessible than it has been in the past.
Cancer in the family
If you have a first-degree relative – a parent, sibling or child – with a cancer that tends to run in families, you may wonder about your own risk and if you can reduce it.
Patients with a genetic risk for cancers of the breast or ovaries, for example, may start screening for breast cancer as early as their 20s or take medications such as tamoxifen to lower their risk. Some may undergo surgical removal of their breasts, ovaries and fallopian tubes pre-emptively to decrease their lifetime risks for cancer.
Genetic counselors also have tools to estimate someone’s lifetime risk for breast cancer, even when genetic testing can’t identify any genetic risk factors, Spencer explained. Genetics is only part of how a woman’s risk for breast cancer is estimated, and certain algorithms can determine a woman’s lifetime risk for breast cancer based on personal and family medical history.
These algorithms can determine if a woman qualifies for earlier and more frequent breast cancer screening.
Spencer also explained that although breast and ovarian cancers are the most common patterns of hereditary cancer, there are many different patterns. For example, another relatively common pattern of hereditary cancer involves increased risks for colon, uterine, ovarian and other gastrointestinal cancers.
Anyone with a mutation in one of these genes may start colonoscopies as early as their 20s and have more frequent colonoscopies throughout their lives. In addition, certain rarer genes related to colon cancer can cause hundreds to thousands of colon polyps and may even require colon surgery to prevent the development of cancer. Genetic counseling provides information to help you decide about these and other pre-emptive strategies, including lifestyle changes like quitting smoking or losing weight.
Genetic Counseling for Cancer Patients:
If you are diagnosed with cancer, the Novant Health nurse navigator who gives you your biopsy result will ask about your family history and weigh the need for genetic testing. He or she will also set up your first appointment with a genetic counselor.
At that appointment, be prepared to discuss your family's cancer history — if any. Gather as much information on biological relatives as you can: type of cancers, age at diagnosis and results of any genetic tests they have had.
Genetic testing will help your doctor develop a treatment plan that gives you the best chance for success.
If your test finds a genetic risk
Your counselor will help you understand what your result means for you and your family. Each gene has its own pattern of related cancers, Spencer and Mayers pointed out, and recommendations vary depending on such factors as age, family history, and whether you already have cancer.
If testing uncovers a genetic risk, don't keep your family in the dark. Let your relatives know. Your first-degree relatives typically have a 50% chance of carrying the same genetic mutation. Your genetic counselor will help you determine which of your other relatives could also benefit from genetic testing.
If you find this important conversation to be difficult, Mayers said, your genetic counselor can provide a family letter summarizing the genetic risks for you to share with your family members.
Changing tech, changing advice
As the science evolves, so too do testing recommendations. For example, breast and ovarian cancer testing that included only BRCA1 and BRCA2 genes is now considered out of date. Spencer said women who were screened for breast cancer risk based on those genes alone should consider an updated test that also looks at other genes.
"We're learning more about genes and the risks that are associated with them as they're studied more and we see them in more people," Mayers said. "We're testing significantly more now than we were 10 years ago."
What About DIY Genetic Tests?
Popular do-it-yourself test kits may be better suited to filling out your family tree than assessing your health risks, according to genetic counselor Christopher Spencer. These tests are called direct-to-consumer (DTC) tests, because they are ordered directly from a company rather than a medical professional.
Although at least one popular commercial kit does look at a couple of specific cancer mutations, for the most part DTC tests are not focused on medical information, he said.
You might discover a long-lost relative and learn along the way that he or she had cancer, of course. But Spencer and his colleague Megan Mayers said that those seeking to learn about medical information such as cancer risk should see a medical professional to coordinate this testing, rather than use a DTC genetic test.