Genetic testing

Friday morning I had a genetic counseling session. I was really worried I wouldn’t be able to make it. I was in serious pain the night before from my expansion and woke up feeling nasty from taking pain meds on an empty stomach. Luckily, a little breakfast and a nap on the couch made me feel human since it would be a couple of months to get another session.

Because I was diagnosed with cancer before I was even 40, I am a candidate for genetic testing. Before you even go in for testing, you have to do a family history – name, age and health (any cancer, reason for death) for myself, my siblings, my parents, aunts, uncles and cousins, and my grandparents and their siblings. I could guess up to my parents’ generation, but had no clue on my grandparents’ generation. After a phone call to my mother, who had some genealogy information for both sides of the family, I was able to finish the paperwork.

The genetic counseling session was a teleconference with a nurse from Magee Women’s Hospital in Pittsburgh. I really appreciated not having to drive to Pittsburgh to do the test (in fact, that might have been a deal-breaker for me). The counselor’s goal is to ensure the person getting tested understands what the test is looking for and what it means if it comes back positive or negative.

The test is solely for the BRCA1 and BRCA2 mutations, which account for less than 10% of breast cancer. The test uses two methods to test for changes in the gene – one to look for mutations in the gene, and a quantitative test to look for additions or deletions. The genes are on two separate chromosomes, and it is very unlikely that you would have both mutations. They are autosomal dominant genes (you only need one copy to get the negative effect) and affect how the cell will repair breaks in your DNA that occur on a regular basis as you go through life. If the test finds a change in the genes (a SNP) that is not the known BRCA mutation, the company keeps the information on file to see if it shows up in other genomes and would be something to pursue.

If the test comes back positive, it increases your risk of developing breast cancer (surprise, but also in the second breast in my case) in both men and women, as well as ovarian or prostate cancer, pancreatic cancer, and melanoma. Using birth control for more than six years significantly reduces (by about 60%) your risk of ovarian cancer, but there’s very poor testing for ovarian cancer so often removal of the ovaries is recommended (reducing your risk by 96%). A preventative mastectomy will reduce your risk of developing breast cancer by 90%, otherwise you start breast cancer screening at 25 with twice yearly physical exams, and yearly mammograms and MRIs.

The test itself was extremely simple – swish with Scope and spit into a tube. I couldn’t eat or drink anything an hour before the test and I had to make sure I got at least 20ml, but that was the extent of the test. Based on my family history, I’m looking at a 1% chance of having a BRCA mutation, but it’s still worth testing, mainly for family members. I’ll get the results in a couple of weeks!