What is genetic testing?
Genetic testing is looking at specific genes that are known to increase a person’s lifetime chance of developing cancer. This involves taking a blood sample and examining the DNA to determine if there is a genetic mutation. DNA is the genetic material that makes up genes and a genetic mutation is a change in a gene that causes it to work improperly. When a specific gene works improperly it can increase a persons risk to develop cancer. Scientists and doctors have not yet identified all of the mutations that can increase cancer risks. In addition, most cancer develops simply due to chance, or non-inherited reasons, so not having a known genetic mutation does not guarantee that you will never get cancer. The genetic mutations we can test for are considered to be “predisposition” genes, which means that someone who has one of these mutations is more likely to get cancer than someone who does not have the mutation. However, it does not mean that cancer will occur.
Testing someone in the family who has had cancer is important in determining whether a cancer-causing genetic mutation is contributing to the cancer in the family and is recommended before testing other family members who have not developed cancer. Recommendations for cancer screening and medical management for many people in a family can be based on genetic test results. (White paper, Huntsman Cancer Institute, 2012)
Because my Mom and Omi (my Mom’s Mom) are both victims of a gynecological cancer, my Mom was a candidate for the BRCA1 genetic test. This test determines if there is a genetic mutation in the BRCA1 gene, thus increasing your risk of breast and ovarian cancer.
Having a BRCA1 mutation increases a woman’s for developing breast and ovarian cancer above the general population risk. We all have two copies of most genes in each of our cells, including the BRCA1 gene. We inherit one copy from our mother and one from our father. When the BRCA1 gene is working properly in the body, its product appears to act as a tumor suppressor. When one copy of the BRCA1 gene has a mutation, it cannot function properly. This results in an increased risk of cancer.
On December 18th, my Mom’s 79th birthday, we received the results of her BRCA 1 test… she was positive.
Women in the general population have a 10% lifetime risk to develop breast cancer. The lifetime breast cancer risk in women with a BRCA1 mutation is approximately 50-85%. Women with a BRCA1 mutation who have already been diagnosed with breast cancer also have an increased chance to develop a second, entirely new, breast cancer. The lifetime ovarian cancer risk in women with a BRCA1 mutation is around 40-60%.
I spent a few days in December making copies and sending out a letter that was distributed to my Mom’s siblings and to my siblings. We had discovered that we were now all at risk of this gene – the Opfermann family that is.
The good news: we now know what we are facing. Although that doesn’t help my Mom’s situation (I would give anything to reverse time with this information), it does help my Mom’s siblings to make informed decisions about testing. And it also gives my Mom’s children and the offspring of my Mom’s siblings, a chance to find out if they carry the gene. If they are tested, and test positive, they will have an opportunity to make informed decisions about what to do in order to potentially avoid these deadly cancers.