BRCA Genetic Testing

As you can see from the above table, the chance of getting breast cancer before the age of 50 is 2% if you have NO family history and don't carry the defective BRCA1 or BRCA2 gene.  However, what if you are diagnosed with cancer and there doesn't seem to be any rhyme or reason to it?  One of your big questions may be "why have I got this?".  In many cases you may never find the answer and it's just one of life's curve balls that gets thrown at you.

However, there have been defective genes identified that, if you're a carrier, would mean your risk of getting breast and/or ovarian cancer are higher than the general population.  These genes are called BRCA1 and BRCA2 (pronounced bracca) and the most famous carrier is Angelina Jolie who has had preventative surgery.  For carriers of BRCA2 the risk is for both breast and ovarian cancer.  People with one or other of these genes have a much higher percentage of getting breast cancer as can be seen from the middle column in the graph above.

You might think that having a strong family history of breast cancer will mean you definitely carry the defective gene but actually that's not always the case.  Even with mothers, aunts, grandmothers who have all had breast cancer, it doesn't necessarily mean that you will - or that you'll carry the defective gene.  Interestingly, it can work the other way round as well.  You might be a carrier and have absolutely no history of breast cancer in your family.

What is absolutely definite is that genetic research is still in its infancy and geneticists will tell you that there are thousands of unidentified genes.  More are being discovered every year and at some point we may all have answers as to why we have got breast cancer.

Should you be tested?

So, should you be tested?  Well, firstly, I need to be very clear here that genetic testing should be up to the individual  - for some there is a "need to know" especially if they've got breast cancer without any obvious family history, and for others there may be a high instance of breast cancer in the family and they want to know so they can decide whether to have preventative surgery or not.  Unfortunately, not everybody will be offered genetic testing - I think it depends very much on where you live, your medical and family history etc.

If you decide to be tested, you shouldn't go into it without giving it a lot of thought.  For example, if you have got breast cancer and have children and are carrying the defective gene, this, potentially has implications for your children.  Could they carry it too? Also, if you are BRCA2 positive, this has implications not only for breast cancer but also ovarian cancer.  So sometimes, the answer can throw up more problems and this must be understood before you are tested.

My experiences of BRCA testing:

I have had the test and am BRCA1 and BRCA2 negative despite my geneticist being almost certain it would come back positive!  I had an appointment with him that took over an hour and we discussesd my family history, my medical history, current breast cancer diagnosis etc and he then took my blood and off it went for analysis.  Waiting for the result I was nervous - actually not for me but for my daughter.  If it came back as negative then I had no reason as to why I had got breast cancer but if it came back as positive and I was a carrier then that had implications for my daughter and that worried me more than anything else. 

For me, the genetic testing actually gave me a route forward for planning how to handle my breast cancer.  Even though I was BRCA negative, looking at all of my medical and family history, the geneticist concluded that, over the course of my lifetime, I had a 20% risk of recurrence.  When you think that the average risk (as shown above) is 2-7%, 20% is quite high.  Also, 20% is the threshold (in the area where I live) where surgeons will discuss preventative mastectomies with patients. 

As I have/had (I never quite know what to say here!) triple negative, grade 3, very fast growing breast cancer, and have a 20% chance of recurrence, for me it's a no-brainer and I have opted to have a double mastectomy with reconstruction as soon as my chemotherapy has finished.  I actually feel very comfortable with my decision because I feel like I'm being proactive with my health.

Of course, having a mastectomy does not mean you can't get a recurrence in the chest wall or scar tissue of the breast but it does mean that my chances of this happening are greatly reduced.

The future:

Out of interest, I was researching the BRCA gene and also found that you can be tested in the UK for an alternative defective gene called PALB2.  It's quite expensive (between £600 and £800) but it does give other information.  I've also found an article on different genes written by the Hong Kong Medical Journal that you may find interesting.