Mayo Clinic medical information and tools for healthy living

Connect with an expert

Genetics blog

With Mayo Clinic genetic counselor Carrie A. Zabel, M.S., C.G.C.

Back to posting index

October 24, 2008

Know your family history in assessing breast cancer risk

3 comments posted

Read comments | Post a comment

By Carrie A. Zabel, M.S., C.G.C.

Being that October is National Breast Cancer Awareness month, I decided to focus this week on assessing hereditary risk for breast cancer. Many people have a personal or family history of breast cancer and wonder how this will affect their future cancer risk or that of their family members. One of the keys to assessing your breast cancer risk is knowing your family history.

It's important to know that most breast cancer is not caused by a single gene predisposition, such as BRCA1 or BRCA2 (two genes widely publicized by the media). The majority of breast cancer is caused by the interaction of both genetic susceptibility factors and environmental factors; we call this multifactorial inheritance. There is no genetic testing available for families with multifactorial breast cancer yet, as the genes with a mild or moderate impact are not yet known, but research is focused on better understanding these families.

In the 10 percent of breast cancer which is thought to be caused by a single gene predisposition, or a strong genetic factor, red flags in an individual's personal or family medical history include:

Early-onset breast cancer (before age 50)
Ovarian cancer at any age
Cancer in 2 or more close relatives
Multiple or bilateral primary tumors
Cancer appears to affect every generation

If you are concerned about your personal or medical family history, you can consider being further evaluated and educated by a genetic counselor. To locate one in your area, go to the National Society of Genetic Counselors Web site (see below) and click on the "Find a Counselor" link.

A genetic counselor will discuss your risk for breast cancer and your chance to have an underlying genetic alteration, such as a BRCA1 or BRCA2 mutation. They will also discuss the pros and cons of genetic testing, and what that means to you personally, as well as help facilitate testing, if you should desire.

Please share your experiences in this area.

Add to del.icio.us

Digg This

Add to Technorati

Stumble It!

3 comments posted

Read comments | Post a comment

Back to posting index

October 30, 2008 10:46 a.m.

I have 2 sisters and all 3 of us have had a breast cancer diagnosis. My older siser was age 50, I was also 50 at diagnosis, and our younger siser 54. Two of us have tested negative for genetic predisposition and the third sister has not yet had testing. There is no other family history of breast cancer that we are aware of. Nancy

- Nancy

October 26, 2008 8:56 p.m.

Both my grandmothers have had breast cancer (one before age 50, the other after), and my mother has also had it (age 54). Worries me a bit, though I'm not sure if the worry is justified. I'm currently 27, so only time will tell.

- Jill

October 26, 2008 8:40 a.m.

In 2000-2001, I and two of my first cousins suffered from various degrees of breast cancer. I had DCIS which was in two areas close to each other. I had a lumpectomy and radiation. I took Tamoxifen for 5 years. The two cousins are sisters. One had a radical mastectomy, radiation, chemo, and tamoxifen. The other, I am not sure how radical, or whether she had chemo, but she also had radiation and tamoxifen for 5 years. The former is the youngest, being under 60, and I and the other were (at the time)over 60. What my surgeon found as interesting was that we are cousins on both our mothers' and our fathers' sides of the family. As far as we know, there has not been breast cancer, on their mother's or my mother's sides of the family. We still are reminding all members of the family that mammograms are how our cancers were detected, and so far, we have not had any new cases. I do have a question, although I intend to check out that link. Both of my daughters have had breast implants. One has had an abortion, and now takes prednizone for asthma. She has two healthy pre-teen daughters. The other has had some heart arythmia problems during her pregnancies, but has two healthy children, one of them a girl. Fortunately I have a strong faith, and believe prayers can work. Thanks for reading my story.

- Joyce S.P.