BRCA 1 and 2 testing demystified

September 12, 2008

I must remind everybody that I am not a medical professional and this is my interpretation of the information given to me by somebody much more qualified.  That said, here goes.

Everyone has the BRCA genes.  They are tumor repressor genes that keep our cells from growing wild (cancer) in our breasts and ovaries.  What we’re being tested for is a damaged gene.  This can happen for various reasons which I won’t go into (mostly because I can’t remember that part.)  If your cancer is hormone negative, you are more likely to be BRCA 1 positive.  Hormone positive cancers tend to be BRCA 2.  If you are under 50 with breast cancer, you have a 7.5% chance of having the gene but it is good to remember that only 10% of all breast cancers are hereditary.

What does this mean for me if I am positive for one of the genes?

-the untreated breast has a 50% chance of developing cancer

-there is a 30 – 50% increase in the chance of me developing ovarian cancer

So what can I do?

-continue to be vigilant for any changes in the untreated breast

-prophylactic mastectomy on the untreated side

-transvaginal ultrasounds to check for ovarian cancer

-CA125 blood tests to look for tumor markers

-both tests for ovarian cancer have a lot of false positives and negatives.

-prophylactic oopherectomy (removal of ovaries)

What would I do?

I have a grade III cancer (most aggressive) with 4 positive lymph nodes.  This gives me a 60% chance of microscopic spread of the cancer. All along we have treated it aggressively and I would continue on in that fashion having the prophylactic mastectomy and removal of the ovaries.  I also learned that even if I were to remove the ovaries, I would continue taking Tamoxifen.  (Didn’t know that.)

What does this means for my family?

The genetic counselor said that if I am positive, it is from my Dad’s side so they would want to test him.

My sister and my brother would have a 50% chance of having the gene.  My sister, K, should be tested as soon as possible.  My brother. T,  might want to be tested for it’s ramifications on his future children.

My children would have a 50% chance of having the mutation as well.  When L is in her early 20s she would be tested and receive her first mammogram (which she’s going to get anyway because the rule of thumb is 10 years prior to your mother’s cancer diagnosis).

The stats for T and J would be this: a 6% (up from 3%) chance of developing breast cancer and a 20% (up from 15%) chance of developing prostate cancer.

So that’s it in a nutshell.  I’ve got a few more weeks to wait for the results.  My insurance did cover the testing, which is good.  I also think that the WordPress spell checker should add “oopherectomy” and “transvaginal” since I’m only guessing at the spelling.  Just sayin’.

Crossposted to ThrowsLikeAGirl

Edit 9/13/08 It’s “oophorectomy” with an “o”.  Heh.  I was close.