BRCA1 and BRC2 testing with breast & ovarian cancer in same patient

[Aglaia]

Hello -

My mom is 57 years old and has both breast cancer (stage I, grade II) and ovarian cancer (stage IV, grade III).  Both were diagnosed withina  few months of eachother and doctors told us that they are indeed separate cancers (i.e., it's not the breast cancer that metastasized to the ovaries).  The gyne oncologists have also become interested in me and had started throwinga round genetic testing for my mom for BRCA1 and BRCA2 a few months ago.  At first I was very scared about it, but, being 34 years old and with no children yet, I feel that I need to find out results so that I can plan ahead.  We have filled out the family history questionnaire, and found that my mom has had 5 aunts who have also had ovarian cancer.  This scares me, and I am wondering if that means that I'd almost be 'guaranteed' to have the mutation.  These are some questions I haven't been able to find answers to yet, so am hoping someone can shed some light:

1) If the same person has both breast cancer and ovarian cancer, what are their chances of this being genetic vs. sporadic?  (Looking for percentages here).
2) If this patient does have the BRCA1 and/or BRCA2 mutations, what are the chances that is has been passed on to me?  (Looking for percentages here).
3) If I am later found to have the BRCA1 and/or BRCA2 mutation, how much does that increase my chances of developing breast and/or ovarian cancer in my lifetime?
4) What precautions can I take to decrease my risk?  I have been on a combined birth control pill for over two years.  Does it matter exactly which one takes to decrease one's risk?  (I am on Yaz).

I am terrified of being told that I should have my ovaries and whatnot removed by, say, age 40.  Mr. Right is nowhere in sight for me, and beinga ble to have children has been a lifelong dream.  Part of me wishes now that I hadn't put my career ahead of family for so long.  This disease really is difficult to deal with.

Thank you!
Aglaia

[Annekathryn Goodman, M.D.]

Hi There
thank you for your excellent questions

10 percent of breast and ovarian cancers are hereditary . The remainder are sporadic
10percent of these cancers are associated with BRCA mutations

your mother should definitely have gene testing.
If your father does not have a mutation, you have a 25% chance of inheritance.

with your family history, even if your mother is BRCA negative, there may be an increased risk for these cancers for you

the single most effect prevention of ovarian cancer is the surgical removal of ovaries and fallopian tubes
This should be done in your 40's after you have finished your child bearing
Birth control pills do reduce the risk of ovarian cancer and are recommended for women who are not trying to conceive until they have the ovaries removed.
best wishes

[Aglaia]

Thank you so much for your responses!   This is the most detail I've gotten about this yet.  One more question though:

If my dad doesn't carry a BRCA1 or 2 mutation, but my mother does, wouldn't that mean I have a 50% of having inherited?  I'm not clear how it would be 25%.

Thanks again!
Aglaia

[Annekathryn Goodman, M.D.]

Hi there
here are my thoughts and answers to your questions

1- no
2- all women have some risk of developing cancer. one in 70 lifetime risk
3 - the rec is to remove the ovaries 10 years before the age of diagnosis in the family member
4- oral contraceptive pills are associated with a 50% risk reduction. There is no information about a particular brand or type of OCPs being better than another

best wishes

[Aglaia]

Hello -

Thank you for beginning to shed some light on this.  A couple of follow up items:

1) If 10% of breast and ovarian cancers are hereditary, would I carry twice that risk because my mom has both?
2) If I do not carry the gene, where does my increased risk come from?  
3) Would it be reasonable to put off removal of ovaries and fallopian tubes until age 45?
4) Are specific birth control pills better than others to decrease risk?  Should they be combination pills?

Thank you,
Aglaia