Vail Health Feature: A Test To Assess Cancer Risk

Vail Health Feature: A Test To Assess Cancer Risk

For some taking a test to determine your risk of cancer could be a lifesaver. For others an inconclusive result could only cause more worry and anxiety. These are just some of the things one must consider when deciding to undergo predictive genetic testing which is used to identify gene mutations that may put someone at risk for a disease such as breast ovarian or colon cancer. Christine Barth certified genetic counselor at Shaw Regional Cancer Center in Edwards said predictive genetic testing is not a simple procedure and there are many decisions involved even before testing begins.

“It's a process that requires a lengthy visit” Barth said. “It's not a five-minute consultation. It's not like saying 'We have a test available would you like it?' It's not like seeing if you have strep throat.”

EXAMINING FAMILY MEDICAL HISTORY

At the Shaw Center Barth will screen both those who've been diagnosed with cancer and unaffected patients. Barth said about 30 percent of her unaffected patients are self-referrals such as someone who recently had a family member diagnosed with cancer and wants to access their own risk. For unaffected patients the first step is looking at three generations of family medical history which includes not just immediate family but also aunts uncles and cousins.

“Sometimes people have concerns that are higher than their actual risk” Barth said. “Sometimes it's lower than they think it's going to be. (They might think) 'Wow everybody in my family has cancer'. When we start looking at what types of cancer are occurring (such as) the generation above us there are seven people in the family and five were smokers. Four or five of those smokers had lung cancer (likely due to) the unfiltered cigarettes people used to smoke. ... So that's why we look at what types of cancers are represented. There are certain types of cancers that create a picture of hereditary or family components.”

Barth said some of the things a genetic counselor looks at are if there's a rare cancer in a family member (especially if more than one family member was affected) age of onset (cancers that occur at a younger age than normal) and family size.

“It's not uncommon to have one person in the family with breast or colon cancer” Barth said. “(But) it's not necessarily common for a small family to have three (members with) breast cancer with an early onset.”

UNDERSTAND THE DRAWBACKS

There are limitations to genetic testing Barth said. Genetic tests only test certain genes and segments of DNA. A test that's chosen may not have the gene present in a patient's family. Even if you test every known gene associated with a specific type of cancer there may be a new gene not yet identified that's not on the test. Because of this a test that comes back negative does not necessarily mean that there's no genetic risk of cancer or the results may be inclusive.

“When we're testing a patient who is unaffected if she has a negative test we aren't sure whether her test is negative or there might be a gene in the family and she doesn't have it” Barth said. “If no one else in the family has been tested we don't know if we're testing the right gene.”

Dr. Alexander Urquhart medical oncologist at Shaw Regional Cancer Center said genetic testing is more advanced now than it was 10 years ago. In the past when testing for breast cancer they were only able to test the BRCA1 and BRCA1 genes. Now they can check for 20 to 30 gene mutations in addition to BRCA1 and BRCA2. Urquhart said with certain genetic-related diseases the main limitation is lack of preventative measures a patient can take if a test comes back positive.

“There are some genes that you can test for in other diseases where you can't really do much (in terms of preventing the disease)” Urquhart said. “Like when you're looking at certain neurological diseases or commercial testing available for Alzheimer's.”

TAKING A PROACTIVE APPROACH TO PREVENTING CANCER

Even though genetic testing can't always provide a clear answer one of the main reasons a patient considers finding out their hereditary cancer risk is to be proactive Barth said giving them more information about both their family medical history and what they can do if a genetic test comes back positive.

“If you don't know your risk you're not necessarily going to know what your options are” Barth said.

In the instance of breast cancer and ovarian cancer once hereditary breast and ovarian cancer risk is identified patients can then discuss their preventative surgery options such as prophylatic mastectomy removal of the ovaries or fallopian tubes or both. Barth said for some surgery isn't necessarily the next step and others may simply opt for further screening.

“If they have a positive test it's not that they decide to not do anything” Barth said. “The choice they make is they're delaying whatever the course may be. I met with a 35-year-old woman last week. She's four months pregnant and had a positive test result (for BRCA2). She's busy adding a fourth child to her family. For her that's her priority right now — pregnancy childbirth breastfeeding. ... We'll meet in a year and at that point we'll talk about what the next step is.”

'KNOWLEDGE IS POWER' VS. POTENTIAL MENTAL ANGUISH

In March Angelina Jolie Pitt published an op-ed in the New York Times revealing that she'd chosen to have her fallopian and ovaries removed because she carried a mutation of the BRCA1 gene. The actress previously underwent a preventative double mastectomy. Jolie Pitt lost her mother grandmother and aunt to cancer.

“I did not do this solely because I carry the BRCA1 gene mutation” Jolie Pitt wrote. “A positive BRCA test does not mean a leap to surgery. ... There is more than one way to deal with any health issue. The most important thing is to learn about the options and choose what is right for you personally.”

Urquhart said for some women preventative surgery (like removing the breasts and ovaries) is the right option for them.

“(These surgeries) have been associated with a marked reduction in risk” Urquhart said. “(For) women with BRCA mutations it's even been shown to improve survival. More women are alive because of these prophylactic surgeries.”

Some like Jolie Pitt view the decision to get a genetic test as “knowledge is power” she wrote. But not everyone with a medical family history of cancer sees it this way.

“(Part of genetic counseling) is a psychological assessment” Barth said. “'Is the patient ready for testing?' Some patients will come in for counseling and after they get the information they self-assess. They determine 'I'm not in a good place for this. I need to wait.' I think that's the reason genetic counseling is so important because it allows the patient to assess 'Do I really want this test? Is it only going to bring on more anxiety?' In a setting where genetic counseling isn't provided that opportunity doesn't exist.”

Unlike an exam you take at school choosing to undergo genetic testing doesn't have a right or wrong answer. However Barth said discussing and understanding genetic testing can help make the decision process a little easier.

“(It's about) being able to make an informed choice “ Barth said. “Rather than having (genetic) testing ordered and not knowing the options on the other end.”

GENETIC TESTING 101

• There are many types of genetic testing but predictive genetic testing involves screening for gene mutations known to increase the risk for certain cancers or to confirm a suspected gene mutation in a person or family. Some common cancer-related genetic tests include screenings for breast ovarian and colon cancer.

• Currently the Affordable Care Act covers genetic counseling and testing for patients with an increased risk for HBOC (Hereditary Breast and Ovarian Cancer). Insurance coverage for other types of genetic testing varies.

• Genetic testing is used to identify the BRCA1 and BRCA2 gene mutations which increase a woman's risk of developing breast cancer by 55 to 65 percent with BRCA1 and 45 percent with BRCA2. For ovarian cancer a woman's risk is increased by 39 percent for BRCA1 and 11 to 17 percent for BRCA2.

• A key component of determining whether or not to do genetic testing is your family medical history. However those who are unsure of their family history shouldn't stress said Christine Barth certified genetic counselor at Shaw Regional Cancer Center in Edwards.

“Most cancer ... is not hereditary” Barth said. “We shouldn't cause anxiety in people because they don't know their family history.”

If you don't know your family medical history Barth advises following the average risk guidelines for the general population such as women should get a mammogram once a year after age 40 and both sexes should get a colonoscopy every 10 years after age 50.

• Colon cancer has a hereditary component of five to 10 percent Barth said. Similar to breast cancer there's an increased risk of colon cancer if one or more first-degree relatives are diagnosed (parents siblings or children).

• If you're concerned about your hereditary risk for cancer Barth suggests consulting with a physician to learn about the screening process. Additional information provided by the American Cancer Society.

For more information on genetic testing visit www.shawcancercenter.com