Debunking Genetic Testing Myths Webinar
July 12, 2021
Outcomes4Me sat down with Dr.Tuya Pal, a Professor of Medicine and an Ingram Professor of Cancer Research at the Vanderbilt University Medical Center, to debunk myths surrounding breast cancer as it pertains to genetic testing. We have included the entire webinar video above for anyone who missed it and wants to watch it in full.
Here is a recap of the key takeaways from the discussion with Dr. Pal:
I already have breast cancer. Why should I get genetic testing done? What’s the point?
This is a common misconception that we see. If you’ve already had breast cancer, you are through your treatment and we’ve identified an inherited cancer gene mutation, that could give us a glimpse into what other cancers are you at a higher risk for. With that information we can be more diligent with your care, whether it’s through cancer prevention or screening.
The other aspect to this is that with genetic testing, we like to start with the person in the family who has had cancer. Starting testing on the individual with cancer has personal health implications, but also is a huge service to their family. If you are positive, then it gives you an opportunity to share this with your family members who can then be tested. You could save the lives of at-risk family members by knowing this information. Alternatively, if you’re negative, your family members really do not need to be tested, unless there is cancer history on the other side of the family. Again, testing individuals with breast cancer is helpful from a personal and family stand point.
Why is it important to even identify inherited cancer genes like BRCA1 and BRCA2?
We have a tremendous opportunity to save lives if we identify individuals with inherited cancer genes prior to the development of cancer and even after development of cancer. About 10% of all breast cancers are inherited. Yet, these breast cancers happen in about 0.3% of women so you can see the disproportionate burden of breast cancer that is imparted on individuals who have a BRCA mutation or an inherited form of breast cancer. Identifying when someone has an inherited cancer through testing gives us information about the types of cancer they may be at higher risk for. In the case of the BRCA mutation, there is a higher risk for breast and ovarian cancer in women. This cancer risk information gives us guidance on the types of prevention or treatment options we may offer individuals.
Bottomline is knowing about inherited cancer can save lives through cancer diagnosis, targeted treatments, prevention or sharing results with at risk family members.
Common Misconception: I had 23andMe, Ancestory.com or another direct-to-consumer genetic test so I do not need to have genetic testing again.
Direct to consumer testing versus clinical testing is very different. At home, direct to consumer testing doesn’t require a medical provider, the scope of results is limited, the results need to be confirmed by a traditional testing laboratory and you can request the raw data from this. Clinical genetic testing does require involvement of a medical provider, it’s usually provided in the context of some counseling, there is insurance coverage if the individual is at high risk, there are many relevant tests that can be offered and interpretation is refined based on personal and family history.
Testing through 23andMe is only limited to three mutations. If you think of the BRCA1 and BRCA2 genes as big books, there are essentially three spelling mistakes in those books that are looked at. However, there actually exist thousands of potential spelling mistakes that can be identified in an individual. You’re getting very limited testing when you have BRCA testing through 23andMe. In addition to BRCA1 and BRCA2, there are a number of other inherited cancer genes that are not looked at all through 23andMe testing. Testing is very different when you go through 23andMe. It is recommended that direct to consumer testing results are validated through clinical testing.
Common misconception: The only breast cancer in my family is on my father’s side so I have nothing to worry about.
That is not true. Just like women, men can pass on inherited cancer genes. For example, there is a grandmother who had ovarian cancer and a granddaughter with breast cancer at age 35. When you do the testing, the father has not had cancer, but he is the one who transmitted the mutation. You need to look at the side of the family where the cancer is coming from. It’s 50/50 whether it came from the mother or father. It really depends on where the family history is.
Are diet and exercise factors in preventing cancer or does the BRCA2 gene far out way those specific precautions?
We always encourage people to have a healthy lifestyle. The issue with BRCA is that even if you reduce your risk a little bit with these lifestyle factors, the risk with BRCA is so high, you’ll still need to be proactive with screening, preventive options or other choices. No lifestyle modification would be enough to say, you’ve gone back to the general population risk.
In individuals with a BRCA mutation, we advise breast cancer risk management such as screening through mammograms and breast MRIs as well as preventative surgery. In people with BRCA1 and BRCA2 mutations, we recommend breast MRIs starting at age 25 and then mammograms starting at age 30 added to the MRIs. For other genes such as ATM or CHEK2, we start screening at age 40. Another cancer risk management option for a BRCA carrier is risk-reducing mastectomy and then salpingo-oophorectomy, meaning removal of ovaries and fallopian tubes. These measures can reduce a BRCA carrier’s risk down to pretty much general population risk. Overall, a healthy lifestyle is good, but does not replace cancer risk management.
If you are looking for more support, resources, or have additional questions, submit your question using the “+” button on the 4Me tab and clicking on “Ask Outcomes4Me” in the Outcomes4Me app. Our O4ME clinical care team will do their best to help you find an answer.