[2021-04-09] Genetic testing results
Two weeks ago, in my post Blue sky, I shared the sadness I was feeling at the time because of the enormity of what I was facing. What I didn't share then is that, the day before, I had learned the results of my genetic testing: I am a carrier of the BRCA2 gene change, sometimes called a gene mutation.
BRCA is a human gene that suppresses tumours. We all have that gene, but some people inherit mutations in these genes and are therefore at an increased risk of developing cancer, particularly breast and ovarian cancer.
As I explained last October in my posts Messy and magical and Genetic testing, analysis of my tumours determined that they contained the BRCA2 gene change. Because of this, I was offered and accepted genetic testing to determine whether that gene change was in only the tumours or all cells of my body. Testing confirmed that it is, in fact, in all cells of my body, which means that I inherited the gene change from my mother or my father.
The Children's Hospital of Eastern Ontario (CHEO), which runs the regional genetics program, tested my blood sample for a total of 17 gene variants, including the BRCA2 gene change. In addition to confirming that I am a carrier of the BRCA2 gene change, CHEO identified that I have another gene variant, known as MSH2. However, because the MSH2 variant is of unknown clinical significance—meaning it may or may not cause disease—no further action will be taken in relation to my healthcare or testing for family members. The variant is simply noted in the event that research in the future determines that it is a gene change of clinical significance.
BRCA1 and BRCA2 were the first two genes that were found to be responsible for some hereditary breast cancers and some hereditary ovarian cancers. Notwithstanding the fact that BRCA is an abbreviation for breast cancer, these gene changes can be implicated in other cancers, including ovarian cancer and prostate cancer. Other cancers where the risk may be slightly elevated are cancers of the skin, blood, pancreas, stomach and gallbladder, though the risk is small.
American actress Angelina Jolie is perhaps the best known BRCA carrier. She revealed in a 2013 New York Times op-ed that she has the BRCA1 gene change. Her mother died from ovarian cancer, and her mother's sister died of breast cancer. To reduce her risk of breast cancer, Jolie opted for a double mastectomy with reconstructive surgery. She also elected to have her ovaries removed to reduce her risk of ovarian cancer.
It would be easy to conclude that a BRCA gene change impacts only women. However, that's not the case. For instance, men who inherit the BRCA2 gene change are at a slightly higher risk of developing prostate cancer and breast cancer. And they can pass the gene change on to their children. So both male and female relatives of confirmed carriers of gene changes are offered genetic testing.
I decided to wait to reveal the results of my genetic testing until I could share the outcome with my close family members. I also wanted to discuss the implications with my oncologist. Today, I had a follow-up appointment with Dr. Le, who, at my request, referred me to a breast surgeon for a consultation. I have already been referred to the high-risk portion of the Ontario Breast Cancer Screening Program for annual mammograms and MRIs.
On the plus side, Dr. Le said that my CA125 number of 8 is excellent and that I am exactly where he would want me to be. He had no concerns with my blood work and noted that I am adjusting as expected to the Lynparza drug.
I was initially saddened when I got my genetic testing results, but I've had a few weeks to come to terms with the information. My test results didn't change the reality that I've had the BRCA gene change since birth; they simply provided me with information that I can use to make decisions regarding additional breast screening and potential preventive surgery.
Equally importantly, my results open up the possibility of genetic testing for family members, which could provide life-saving information to them that I didn't have.
That said, it's important to note that most people (90%) who develop cancer have not inherited a gene change that predisposes them to cancer. In other words, 90% of cancers are not considered hereditary. They are caused by many risk factors, such as age, chance and environmental factors. However, when one type of cancer is diagnosed in several individuals from different generations in the same family (e.g., mother-father-aunt-uncle then daughter-son-niece-nephew), an inherited gene may be the cause. Genetic testing can confirm the presence or not of a gene change.
So, just as I am trying to raise awareness of ovarian cancer, I would encourage anyone offered genetic testing to avail themselves of the option. Like Angelina Jolie, I believe that sharing my story may help others.
And if nothing else, I hope that I am demonstrating that one can smile, laugh, love, celebrate and live even with cancer.
