BRCA1 & BRCA2 – The Unraveling of the Mystery

June 17th, 2011

One thing I learned today is that everyone carries the BRCA1 and BRCA2 gene. I think I had assumed that if you had those genes you were at a higher risk for early onset breast or ovarian cancer, but it’s only if you have a deleterious mutation of those genes that you have a higher risk – up to 80% chance during your lifetime .

The function of the BRCA genes is to repair cell damage and keep breast cells growing normally. But when these genes contain abnormalities or mutations that are passed from generation to generation, the genes don’t function normally and breast cancer risk increases. Abnormal BRCA1 and BRCA2 genes may account for up to 10% of all breast cancers, or 1 out of every 10 cases.

Another interesting fact is that the Ashkenazi Jewish population (which make up 80% of all Jewish peoples – Jewish people with origins in Europe) and Norwegian, Dutch, and Icelandic peoples have a higher occurrence of a mutation in the BRCA1 and BRCA2 genes.

I also learned that a BRCA mutation can originate with a new individual. For example, I have no family history of breast cancer, early onset or otherwise. I do have family history of late onset colon, stomach, and lung cancer but those cancers are more likely environmental or lifestyle related. However, my BRCA genes could have mutated on their own, but it’s pretty unlikely. Based on my risk assessment I have a slightly higher risk of developing early onset breast cancer – about 6% – which is higher than the general population. Of course that risk assessment is completely incorrect because I DID in fact develop pre-menopausal breast cancer.

I had blood drawn today to send to the Myriad for BRCA gene testing to find out if I have a deleterious mutation.

So what if the test results come back positive? Well there are a lot of decisions I would be faced with. Removal of my left breast, removal of ovaries and/or fallopian tubes, and/or more frequent screening for both breast and ovarian cancer. Unfortunately there aren’t very good ovarian cancer screenings available. I have already decided if a positive result is returned, I will opt to remove the other breast and my ovaries, unless of course my surgeon disagrees with that thought process.

The next concern is how to address my two young girls, 7 and 8. Genetic testing isn’t done on children younger than 18, but I would encourage them to be tested at 18, and help them make the decision about what to do based on their results. That’s quite a ways a way and hopefully there will be more advances in treating breast cancer and they won’t be forced with the kind of decisions I am forced with. I have already had all the children I planned to have, and have no use for my ovaries any longer. I would be very sad if they had to make the choice to remove ovaries or breasts at such an early age. But there are chemo preventative options, in addition to birth control treatments to decrease the chance of developing breast cancer so surgical intervention isn’t the only choice.

I will report back in 7-10 days with the results. Wish me luck!

Below is a chart of the cancer risks with and without the BRCA mutations.

If You Have NOT Had Breast or Ovarian Cancer: Mutation Carrier General Population
Breast cancer by age 50 33%-50% 2%
Breast cancer by age 70 56%-87% 7%
Ovarian cancer by age 70 27%-44% <2%
Male breast cancer by age 70 6% .05%
If You HAVE Had Breast or Ovarian Cancer: Mutation Carrier General Population
Ovarian cancer 15% not available
Breast cancer after 5 years 27% 3.5%
Breast cancer by age 70 64% 11%
  1. Ellen Cobb says:

    I will be wishing the best for you!