BRCA 1 and 2 testing demystified

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.

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8 Responses to BRCA 1 and 2 testing demystified

  1. bcjenster says:

    I’ve been banging around whether or not to be tested, too. I did have prophylactic right mastectomy at time of reconstruction and six months later I had oopherectomy because of wild estrogen. I’m a little surprised at the Tamoxifen after ooph. I had to wait about six months to make sure the estrogen was low, but then I was switched to Arimidex.

    Thanks for this informative post. It gives me something to think about.

    (OH. As a side note – my gynecologist in Little Rock was one of the developes of CA125.)

  2. I was tested and I am BRCA 1 and 2 negative, but I still did the ooph… I never got my period back after chemo and before the ooph… so I am on Aromasin instead of Tamoxifen. I think it is newer drug for post menopausal women. The side effects are supposed to be less than Tamoxifen but there is no bone component so you have to take Calcium and Vitamin D.

    Even though my kids were adopted I still wanted the testing for my sister, nieces, cousins. Someone else could still carry the gene, but they feel since I am the youngest of the siblings and cousins if no one else has shown any signs yet they probably do not carry the gene. It is all so interesting none the less.

  3. Jen says:

    why would it only be from your dad’s side? Was your mom already tested? We were told it could be either but I was negative

  4. throwslikeagirl74 says:

    Jen – the counselor said that if my mom had the mutation that she would have already had BC by now. also the cancer on my mom’s side was mostly prostate late in life where as my dad’s side had a pancreatic cancer and one later in life BC (70s).

  5. Stephanie says:

    I was just diagnosed with breast cancer and will be participating in genetic testing very soon. Thanks for posting about this.

  6. I thought your post was informative and well written.

    I did get tested for the BRCA1+2 mutations. I am negative for that mutation.

    The scientific community knows that there are at least 2-3 other genes, that are connected to breast cancer, that have not yet been identified.

    Given my family history, it seems pretty clear that my breast cancer is hereditary.

    I am currently in a study to, hopefully, identify one of these other genes. My mother also participated in the study. (no big deal, we just had to donate a blood sample)

    My daughters will need to start getting mammograms at age 25.

    (that totally sucks, but what can you do)

    ————————————————————
    OOPHERECTOMY:

    If you do have it, then it is worthwile to check out the other drug options.

    (in Hebrew, “oof!” is an expletive, like “darn!” or “rats!” — kids say it all the time when they have to do something they don’t want to do. Everytime, I hear the word oopherectomy, I have this image of a three year old who doesn’t want to eat her peas!)

  7. Sarah S. says:

    Very good post. I am still confused about all of this. I am triple negative and do not really understand all of the gene testing. My surgeon recommended getting through my treatment before doin the testing. I have three daughters and am afraid for them. Does anyone know anything about being triple negative? no one has really told me about it.

  8. mod*mom says:

    waiting is the hardest, like you’re in the hotseat.

    i tested negative + i’m hoping the same for you.
    it’s so good to know one way or the other.

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