The Importance of Understanding Your Family History of Breast Cancer

NARRATOR: Understanding your family history of cancer is important for understanding your own risk.

About 5 to 10 breast cancers out of 100 are because of a single gene and may run in your family.

We get one set of genes from each of our parents. These genes are like instructions, telling our bodies how to build cells.

The genes most commonly affected in hereditary breast cancer are the breast cancer 1 and breast cancer 2 genes, called BRCA1 and BRCA2. Normally, these genes keep cancer cells from growing.

But sometimes they mutate and don’t work properly, which can lead to cancer.

Everyone has BRCA1 and BRCA2 genes, but only about 1 in every 400 people in the United States has a mutation in either of these genes.

If either of your parents has a BRCA gene mutation, you have a 1 in 2 chance of having the same mutation.

Not everyone who has a BRCA gene mutation will get breast cancer. But these mutations do increase your risk, especially of getting breast cancer at a younger age.

Other genetic mutations can also increase your risk of breast cancer, but they don’t seem to increase the risk as much as BRCA mutations.

Even in families without a known genetic mutation, there may still be a history of cancer.

These cases could be caused by environmental factors, such as exposure to chemicals or a genetic mutation that hasn’t been discovered yet.

If your family has a history of breast or ovarian cancer, you and your family members are more likely to have a BRCA1 or BRCA2 mutation.

Having this information helps you understand your chances of developing breast cancer.

Some groups have a higher risk for a BRCA gene mutation than others, such as Ashkenazi Jewish women and Latinas .

A genetic counselor can help you figure out what your family history means for your personal risk.

While you can’t change your genes, you can lower your risk of getting breast cancer.

Lifestyle choices such as limiting alcohol intake, maintaining a healthy weight and exercising regularly have all been shown to make a difference.

While talking about breast cancer with your family may not be easy, it is important. The more you know about your genetic history, the more you can do to manage your risk.

This resource was created with support from Daiichi Sankyo and Merck.