Ask the experts: Does genetic testing make any difference?

March 20, 2018 Providence Health Team

 

Genetic counseling and testing can be used to assess cancer risks

Anyone is a candidate for genetic counseling if they have concerns about their risks

Genetic tools should be empowering, not a cause for fear


The field of genetic medicine is fascinating — what once was considered futuristic is now a valuable way for people to determine their risk for different cancers as well as the impact it can have on family members’ health. But this is a complex, evolving field, so it can be tough for people to keep up with what genetic counseling and testing is all about. Here, our experts answer some of the most common questions:

What exactly is genetic counseling?

The process has multiple parts, says Maggie Miller, MS, a certified genetic counselor with Providence Cancer Center in Anchorage, Alaska. “Genetic counseling begins with a medical interview, gathering information on personal and family history-based risk factors. This history is used in an assessment, to determine if genetic testing is warranted and to calculate the patient’s cancer risk. The patient is informed of those risks and whether genetic testing and/or increased screening and management is appropriate. Then, the risks and benefits of testing, as well as screening and management are shared with the patient to help them make an informed choice about how to proceed. The information about increased screening, preventative medications and surgeries, and lifestyle modifications can be very empowering for patients, providing them with a plan to prevent cancer or diagnose it at a more treatable stage.”

Where does genetic testing fit in?

“In many cases the choice to have genetic testing is on the patient and whether they feel it’s going to make a difference for them,” Miller says. And that’s where counseling is so important.

“In the absence of genetic counseling the person may not fully understand what she is having done,” she says. “She could test negative and think she’s at low risk, but a huge part of what genetic counselors do is assess a person’s risk for cancers in their family. Genetics is a puzzle —if people have just one piece, they have no idea how it fits in. We show them the whole puzzle.”

What’s the most important tool for understanding genetic health?

People need to get the best information they can about their family health history, says Ora Karp Gordon, MD, Regional medical director of the Providence Center for Clinical Genetics and Genomics, Los Angeles, and the Department of Integrative Medicine at the Roy and Patricia Disney Family Cancer Center in Burbank, California. 

“Whenever I am giving lectures or doing community outreach, I always say Thanksgiving should be family history day,” Dr. Gordon says. “People should get as much information from their family members as they can — clarifying cancer histories, ages of onset and causes of death.”  She adds that there are several different ways to compile this information; for an example, see the My Family Health Portrait provided by the U.S. Surgeon General. If family members don’t live nearby or can’t recall data, genealogical tools such as death certificates can be helpful from a medical standpoint.

With that detailed information, “We can look at patterns in the family, whether they mean something, and determine how we can take that forward,” Dr. Gordon says.

What types of genetic tests are available?

There are several kinds of testing options. For instance, when someone is diagnosed with breast cancer she is may be offered both germline and tumor testing, says Kimberly Childers, MS, genetic counselor and regional manager for the Providence Center for Clinical Genetics and Genomics.

“Germline testing is for something you’re born with; it’s in every cell of your body,” Childers says. “It’s done using a blood or saliva sample to see what you might have inherited from your family that would cause a risk for breast and other cancers. This testing is usually done in genetics clinics.  Tumor (also called somatic) genetic testing is often done by an oncologist to help target best cancer treatments. Though sometimes tumor testing will identify an inherited change, for the most, these mutations are specific to the tumor and NOT passed down in families.

A third, exciting new area of risk assessment, says Gordon, is now a test that looks at very small variations in a woman’s whole genetic makeup (called SNPs). It is an important tool for women who do not carry what is known as a single-gene mutation, and it can better stratify the individual risk for breast cancer in those women.  This is referred to as genomic risk assessment and will likely be expanded to other cancers in the near future.

Does someone have to be at high risk to get genetic counseling or testing?

“Historically, testing was restricted to people who came from high-risk families with multiple early onset cancers or multiple instances of the same cancer. Those were triggers for a hereditary work-up,” Dr. Gordon says. “What has changed in the last year and a half is that technology has driven the understanding of genetic information, and the cost has plummeted. Testing for BRCA 1 and 2 used to cost almost $4,000 — now for $250 we can test for more than 50 cancer genes at once.”

“So, the access to that information has changed the perspective to start looking at people from a proactive or preventive view,” Dr. Gordon continues. “People can see a genetic counselor and from there get reassurance that they don’t need anything further, or they can get access to what’s considered proactive genetic testing. It’s an extraordinary time for transformation in genetics. There really isn’t a person is who shouldn’t come in to get more information.”

What difference does genetic testing make?

Miller says this is the number-one question she gets from patients. “I think it depends on whether we find a genetic mutation, and what risk is associated with that gene. We may learn of a cancer risk the patient would never have been aware of. For instance, the family has had breast cancer, but the gene mutation indicates a risk of ovarian cancer. We don’t have an adequate screen for ovarian cancer, but we do have preventive surgery.  So, it could inform someone of something that they could do to save their life.”

Genetic testing can also determine a screening schedule different from the norm, Miller says. “For instance, imaging for breast cancer starts at age 40, but for someone with the BRCA gene mutation, it may start at age 25.”

 Does every family member of a cancer patient need genetic testing?

The first person in a family that should be tested is the person with the cancer. “Our first job is to figure out if that person developed cancer because of a known inherited risk factor,” Childers says. “If that person has genetic testing and it comes back normal, it’s incredibly reassuring for the rest of the family.” She does add that if someone else in the family had an early-onset or suspicious cancer, they should be tested as well for a more comprehensive picture of the family’s genetic history.  If the family members who had cancer cannot be tested, those without cancer, should most definitely still get testing themselves.  Genetic testing can still provide great information on risk and optimal prevention strategies.

Do you need to have a strong emotional capacity to undergo genetic testing?

Some people may avoid genetic counseling or testing, fearful of what the results may be, but Dr. Gordon thinks that’s a persistent misconception. “When we do genetic risk assessment it is always directed toward empowerment,” she says. “People have choices in every step of the process. They can be reassured by the findings, and they don’t have to over-test. Or they say, ‘Wow, I didn’t appreciate that my father’s mother’s history of ovarian cancer can have an impact for me and my children and now I want to evaluate that.’”

What about genetic discrimination?

The fear that an insurer or employer can take action against someone with a genetic mutation can also keep people from pursuing counseling or testing. But Miller assures that there are a number of federal protections against genetic discrimination from employers as well as private, small-group or employer-sponsored health insurers.

“They can’t make you do a gene test or use it to raise rates,” she says. “But where we don’t have protections is in life insurance and long-term care and disability insurance.”

Can at-home genetic tests get the same results?

There’s a big difference between clinical genetic testing and direct-to-consumer kits such as 23 and Me and Ancestry.com, Dr. Gordon says. Even though 23andMe offers some carrier testing and now even very limited BRCA testing – the FDA has given 23andMe approval to report breast cancer risk related to 3 specific BRCA mutations most commonly found in the Ashkenazi Jewish population – consumer kits are not comprehensive. Even worse, consumer kits may provide false reassurance or misunderstanding of what testing a person had.  It is not at all the same as someone coming in for hereditary risk assessment.

Are children automatically at risk if their parents have a gene mutation?

We have two copies of every gene in our bodies — one comes from our mothers and one from our fathers. A mutation can come from either parent’s copy. “The other copy is usually totally normal, so when people think about the chances their kids might get this, they’re 50-50,” says Childers. “They could either get the normal copy or the copy with the mutation. If they get the normal copy, this significantly reduces their cancer risk.  Even for those with a very strong family history, may learn their risk is the same as any other person.  This is the power of genetic testing.

And contrary to popular belief, genetic mutations don’t skip a generation. “Most of these genes don’t cause 100 percent risk for cancer,” Childers says. “So we may see the actual cancers skipping generations, but the risk is there.  Let’s say Grandma and Mom both carry a breast cancer gene that has a 50 percent lifetime risk for breast cancer, Grandma might get breast cancer and Mom may not.  This could be due to Mom’s age, or having taken medication, lifestyle factors or simply by chance since risk is not 100%.

Do you need a doctor referral for genetic counseling?

“Asking a doctor is always an appropriate first step for testing, but if folks come across difficulty with that or the doctor isn’t sure if there is a benefit, then being an empowered self-seeker of health care is always encouraged,” Childers says. “In genetic counseling, a significant portion of our patients are coming in because they hear about something on the news or from a friend and they’re just curious. You don’t have to have a mom who had breast cancer at 30 or a dad who had colon cancer at 40 to walk in the door of a genetic counselor. We’re not going to turn people away because a family doesn’t have enough cancer in its history.”

Does genetic testing only determine cancer risk?

Cancer is most commonly associated with genetic testing — think Angelina Jolie and her well-publicized testing and treatment for the BRCA gene associated with breast and ovarian cancers. But genetics is moving forward in many ways.

“Cancer has been the leading edge and has the most number of genes and guidelines for testing, but it has a watershed effect on all common diseases of adulthood,” Dr. Gordon says. “For instance, in a growing area such as cardiovascular disease, understanding the genetic propensity to a whole number of those diseases is something very important to me.”

 

Are you a candidate for genetic testing? Start by reading this questionnaire. For more information, contact the following centers:

California: Providence Center for Clinical Genetics and Genomics

Alaska: Providence Cancer Center

Washington: Providence Genetics Clinic

Oregon: Providence Genetics Risk Clinics

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