Genetics Testing for Breast Cancer and the BRCA2 Gene Mutation

If breast cancer happened at an early age, or if there is a history of breast cancer in the family when you got the news, then your oncologist may recommend genetics testing. My oncologist suggested a visit with a genetics counselor as I was diagnosed with triple negative breast cancer in my early 40s. Turns out, I tested positive for BRCA2 gene mutation.

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This post will go into things to consider for genetics testing, as well as info I learned about the BRCA2 gene mutation along the way. I had to take time in writing this, as it still gets to me. Like, a lot. It is one thing to be diagnosed with breast cancer; it is something all together different to know that each of your kids has a 50% chance of getting it and passing it on. It’s the emotional weight of the diagnosis that is the most painful. I can take all the measures for fighting for myself, but a parent never ever wants to be in the situation to pass on news like this to their kids. It’s awful. I’m waiting until my kids are older to tell them. And I need to get to the point of being okay with it to explain it all to them, so I’m glad they are young. 🙂

Genetics Testing for the BRCA1 and BRCA2 Gene Mutation

Every woman who has breast cancer shouldn’t worry if they carry the gene mutation as BRCA1 and BRCA2 mutations make up actually only a small portion of breast cancers.

Both the BRCA1 and BRCA2 gene mutations are damaged genes that are passed on through the family lines which places the carrier at a higher risk for getting certain cancers in their lifetime. It could come from either side (your mom or your dad’s side), and dads can pass it on to their daughters so don’t think it is only a maternal gene.

Questions for At Risk Women and Who Should Consider Genetics Testing

The answers to these questions will help determine if genetics testing should be considered.

  • Was your cancer diagnosed at an early age? Was it triple negative breast cancer?
  • Was it bilateral breast cancer?
  • Do you have an Ashkenazi Jewish background?
  • Is there breast and/or ovarian cancer in your family background?
  • Is there triple negative breast cancer in the family diagnosed at age 60 or younger?
Benefits of Genetics Counselors

My personal recommendation is to see a genetics counselor first. The advantage of seeing an actual genetics counselor is that that person will literally spell out every detail regarding the genetics testing, and answer any questions you have. They are experts in the field of DNA and genetics and they can explain in detail what gene mutations are. The genetics counselor will actually help you decide if the testing is needed for your case, too, and will help you go back through your family history to see if there is a pattern if you are unsure whether BRCA1/BRCA2 exists in your family. In my case, my genetics counselor through Kaiser was amazing. She was very thorough in her quest to see if this was right for me, answered all my questions (and there lots especially when it came to my children), and was patient and kind in giving me, at the time, the pretty devastating news. I now consider the news a great benefit as I have tailored my breast cancer therapy around it. 

Other gene mutations can cause breast cancer, though, so screening for inherited mutations for genes other than BRCA1 and BRCA2 may be recommended.

Reading the Results

You can be positive, negative, or be a variant of uncertain significance. Positive means there is a shift in the gene code and will be reported as pathogenic. Negative means no variation was detected. Variant of uncertain significance means there is a mutation but isn’t enough to classify it as fully positive (don’t think of it as a positive). If you are negative, you are normal. If you are positive, you are considered a carrier.

Remember: just because you test positive doesn’t mean you will get cancer, and just because a family member tests positive, doesn’t mean that you will, too. Also, just because one person in the family tests positive, it doesn’t mean the entire family will test positive.

Benefits of Genetics Testing

The main benefit of testing and finding out you are negative is you can relax a little about the risk of future cancers and passing it on to your kids. The main benefit of testing and finding out you are positive is that you can be proactive in your cancer journey with drugs and prophylactic surgeries to prevent future cancers from forming. It also gives you a little relief in knowing there is a reason you got cancer in the first place rather than constantly wondering what you did, ate, or exposed yourself to that was the cause. Meaning – there is a genetic explanation of why you got the cancer. If you are positive but have no cancer yet, you can begin your screening for breast cancer at a much younger age than the general population. That is always good news to detecting and treating it early.

Emotional and Psychological Drawbacks of Genetics Testing

This is something personal and will affect different women in different ways. Testing positive will be overwhelming to say the least. And if you have kids, like in my case, this may be the most difficult thing to tackle and deal with, just knowing that you are the reason they may have an increased risk of developing cancer. But remember (as I have to remind myself) it isn’t your ‘fault’. It’s just genetics, baby.

And then you have the task of telling family members and having them react to the news – they will be in two camps: positive and proactive, or filled with anxiety. Remember, this news is private and only you need to deal with it at first. Deal with it first in your own way before you share the news with others.

BRCA2 Positive: What This Means

What is the BRCA2 Gene Mutation?

As I am BRCA2 positive, I will not go into BRCA1. It’s a whole other can of worms that, since I’m negative, I don’t need to open. Basically, we all have the BRCA gene, and the BRCA gene functions to keep cancer from forming in the breast. When a mutation forms it doesn’t work properly, thereby increasing your risk for developing breast cancer. BRCA1 and BRCA2 are two different mutations of the BRCA gene. The BRCA2 gene is located at chromosome 13. If you are BRCA2+, it means there is a mutation for that gene at that spot, and you are at an elevated risk of developing some cancers.

My genetics counselor told me if there was a choice of BRCA1 or BRCA2, then it would be better to be BRCA2 positive. It usually strikes later in life (except in my case lol), and it is easier to treat, or rather, responds better to therapy. I’ll take any good news I can get.

The Basics of BRCA2 Positive

The most commonly associated cancers with this genetic mutation are breast, ovarian, pancreatic, prostate, melanoma, and endometrial serous carcinoma – a rare form of endometrial cancer. The BRCA2 mutation is also called Hereditary Breast and Ovarian Cancer Syndrome.

What are the odds of someone testing positive and developing a cancer? This is from the company who did the genetics testing for me:

  • 41% to 84% risk for breast cancer in women, and 4% to 7% for breast cancer in men.
  • 11% to 27% risk for ovarian cancer.
  • 5% to 7% risk for pancreatic cancer.
  • 20% to 35% risk for prostate cancer.
  • Your chances of melanoma skin cancer is increased.

What are the chances of passing it on?

  • First degree relatives have up to a 50% chance of also having this mutation, which means your kids have a 50% chance of getting this mutation from you, male or female.
Managing Your Risks When BRCA2 Positive

There are a number of ways to use this information in a proactive way. They involve either increased screening or prophylactic surgery.

When you are in your twenties, it is recommended for women to have an MRI or mammogram every other year, then every year after 30. Clinical breast exams by a doctor should be done every 6 months to a year, beginning at age 25. Self exams should be done monthly beginning at age 18 – this is important so that you can notice changes to your own breast early. Full body scans for melanoma cancer should be done. Wear sunscreen and hats and protect yourself from the sun! (Of course, you are doing that already.)

Bilateral mastectomy before cancer develops will reduce the chance of developing breast cancer by at least 90%. I asked my surgeon why it doesn’t just move to 100% since the breasts are removed, and he said since breasts are made of mammary glands and not actual muscle, it is nearly impossible to remove all breast tissue. But 90% is a very good number. If you have had all your kids and you are between the ages of 35 and 40, removing the ovaries and fallopian tubes will reduce ovarian cancer and if done before natural menopause further reduces the risk of breast cancer by up to 50%. Tamoxifen, a hormone therapy, reduces the risk for estrogen responsive cancers.

The Bottom Line With a BRCA2 Positive Diagnosis

…is that it is not the end of the world. Rather, it is the beginning of taking a heightened look at what you are doing for screening and what you can do to prevent a cancer from happening in the first place. At first the news can be devastating, especially when kids are involved, but knowing all the facts makes knowing this news actually beneficial. And since the point is to be around for a long time to come, knowing whether you are positive or negative is something important to know.

Image of flowers courtesy Henry Lorenzatto via unsplash.