Experts explain who should consider genetic testing for breast cancer
Q&A with oncologist, genetic counselor
ORLANDO, Fla. – Many people are familiar with the at-home genetic test kits, but can they identify your breast cancer risk?
To answer that question, and address several other myths about genetic testing, News 6 spoke to experts in breast cancer and genetic testing.
Both interviews have been edited for clarity.
Dr. Rebecca Moroose a breast oncologist who is the director of cancer research and cancer genetics at the Orlando Health UF Health Cancer Center. Moroose discussed the pros and cons of at-home genetic testing.
News 6: What's the difference between doing one of the at-home kits and getting the results, and doing them with a genetic counselor?
Moroose: Huge difference. First of all, a genetic counselor does education for the patient before the test is even done. They also analyze your family tree to figure out if you're the best person to test, or maybe it's mom, or sister who were affected with cancer. So they want to do the right test on the right patient.
News 6: What are some of the genetic components that you test for at the UF Health Cancer Center that people can't test for at home?
Moroose: BRCA -1, BRCA -2, the first known cancer-related genes for breast cancer; now there are about nine total that are significant. And then there are many more, what we call "candidate genes" that have just been found, but that we're determining what the relevance of a mutation in those genes would mean.
News 6: What are scientists learning about new cancer-related genes?
Moroose: There're two pieces to this: One is to look at the family history for red flags for possible inherited cancer syndrome. The other is to look at the personal characteristics -- the height, weight, when menses started, how many children you had and at what age, if you're menopausal, if you take hormone replacement therapy, and your family history -- that we can calculate breast cancer risk based on all those factors. And this might not be a risk because of a gene mutation, but these are so important and everyone overlooks it. They feel like, "If I don't have a gene mutation, I don't have a breast cancer risk," and that is misinformation.
News 6: What about people who don't have a family history of breast cancer?
Moroose: One in 8 women in the United States will develop breast cancer in her lifetime. When I started in practice years ago, it was 1 in 12, then it was 1 in 10, now it's 1 in 8. And the majority of those do not have a genetic risk.
News 6: What if you do get breast cancer, is it still worth it to get genetic testing?
Moroose: It is if you qualify because certain genes confer a risk not just of breast cancer, but other cancer such as ovarian and Fallopian tube cancer. And there are cancer syndromes like the one I mentioned Li-Fraumeni, it suggests you can get breast cancer, but you can get bone cancer, sarcomas, a host of other cancers. Those patients we screen them annually with a head-to-toe MRI looking for brain, looking for bone, looking for other cancers.
News 6: Do you have people who are scared to find out the results?
Moroose: We do have patients that just do not want to know. And so if they maybe had a relative with a mutation, and they had a fifty percent chance of inheriting that mutation. So we tell them two things, yeah you're not forced to do this testing, but this testing empowers you.
News 6: How is genetic testing really a step forward in the fight against breast cancer?
Moroose: Every cancer is genetic, only about 5 to 10 percent is because of an inherited gene, the rest is because something was acquired during your lifetime, a gene went wrong, and caused cancer. So now that we understand that we're now getting a closer look into the biology of cancer, which then leads to better therapy.
Next News 6 spoke with Ryan Bisson, a genetic counselor at the Orlando Health UF Health Cancer Center about how accurate at-home genetic testing can be.
News 6: Do you think everyone should get genetic testing?
Bisson: No, not at this point. Basically, we have 20,000 genes, and we only know what some of them do. So probably, maybe 10-15, maybe even five years from now we may all need to have testing because we all have something in our family. It could be cancer, it could be diabetes, it could be Alzheimer's but we don't know the genetic factors for a lot of those common diseases.
News 6: Who do you think it benefits the most?
Bisson: Breast cancer typically happens like in the 60s or the 70s, but if we see it in the 20s or 30s then we start thinking, "Well, maybe there's some gene mutation in that family that caused the cancer to happen at a younger age." The second group of families are the most common families, the families that have the same cancer multiple times. So if mom and grandmother and aunt all had breast cancer, no matter what age they were diagnosed that makes us concerned. And then the third big group of people are people that have rare types of cancers that are more likely to be hereditary, so only 5 to 10 percent of all cancer is hereditary, but that's all cancer. So if you look at something like ovarian cancer, about 25 percent of ovarian cancer is hereditary. Or prostate cancer, some prostate cancer can be hereditary, pancreatic cancer about 15 percent of it is hereditary. So when we look at these more rare types of cancers, those are cancers that there may not be a strong family history but they qualify for counseling and testing.
News 6: Why is it important to talk to a genetic counselor about genetic testing results?
Bisson: Most of the at-home tests are not medical based. So something like Ancestry.com or National Geographic had an ancestry test it's mostly just looking at your ancestry. Which is more hobby based, but it's not going to really tell you about your risk of having cancer, diabetes or heart disease. But there is one of the big take-home labs that started offering more medical-based tests, but you always have to look at the fine print like you do on anything. So some of the tests are only very specific for some ancestries. So the breast cancer genetic test that the lab will run is only for individuals of Jewish ancestry. So if you don't have Jewish ancestry, you're most likely going to come back negative, but you could have something else that the test did not look for.
Bisson went on to say about 99 percent of the time at-home testing kits are not sufficient from a medical perspective.
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