What is hereditary breast and ovarian cancer?

10-15% of ovarian cancer and 5-10% of breast cancer are hereditary.

To kick off October as Breast Cancer Awareness Month, we’re going to dive into a lesser-discussed topic that bridges the gap between ovarian and breast cancer: hereditary breast and ovarian cancer (HBOC). Many people have a general sense that people with family history of cancer have a higher cancer risk, but do you know why that is?

The answer lies in genetic mutations — changes to the sequence or content of genes in our DNA. We know that a number of genes, including BRCA1 and BRCA2, can have mutations associated with a higher risk for breast and ovarian cancer. While BRCA1 and BRCA2 are the most well-known breast and ovarian cancer susceptibility genes, they are not the only ones.

These genetic mutations can be passed down from one generation to the next, increasing the risk of cancer within a family as well as increasing one’s personal risk of breast, ovarian or other cancers. We know that BRCA1 carriers have a 44% chance of developing ovarian cancer, compared to 1.3% of the general population. BRCA2 carriers have a 17% chance of developing ovarian cancer, compared to 1.3% of the general population. And BRCA mutation carriers have a 50-85% chance of developing breast cancer, compared to 11% of the general population.

So what does this mean for you?

How do I know if I carry a genetic mutation associated with breast and ovarian cancer?

0.2% to 0.3% of the general population carries a BRCA mutation.

A genetic test can indicate whether or not you carry a known genetic mutation associated with breast or ovarian cancer. Most genetic testing companies now look at the sequence of all DNA bases for BRCA1, BRCA2, and many other genes with mutations associated with breast and ovarian cancer.

Should I consider genetic testing?

Consider the below criteria to determine whether you have a higher likelihood of HBOC and talk to your trusted health care provider to see if genetic counseling is right for you. All indicators have to do with family medical history, so you’ll need to talk with your family to learn your family health history if you haven’t already.

To simplify the process, you can download our handy family history worksheet.

In your family research, take special note of the following:

1. General history of breast/ovarian cancer, especially if cases are between generationally close relatives, and/or if breast cancer was diagnosed before age 50.
2. Family member with a young diagnosis of breast cancer. A diagnosis before age 35 is telling of a possible genetic mutation.
3. Both breast and ovarian cancers in a single family member. The two may be genetically linked and can point towards a genetic predisposition.
4. Ashkenazi Jewish heritage. 1 in 40 people in the Ashkenazic Jewish population carry a BRCA mutation.
5. Family member with primary cancer in each breast, especially before age 50.
6. Family history of male breast cancer. It’s rare, but it happens! Men with a BRCA2 mutation have a 6% chance of developing breast cancer, as opposed to less than 1% in men without the gene mutation.
7. Family member with identified BRCA1 or BRCA2 mutation.
8. Family member with pancreatic cancer.
9. Family member with prostate cancer before age 55 or two or more family members with prostate cancer

What you need to know about genetic counseling

Think genetic counseling might be right for you? Here’s what to expect when scheduling an appointment with a genetic counselor:

• You’ll review a comprehensive analysis of your family’s medical history.
• You and your genetic counselor will assess your risk for breast, ovarian and other cancers.
• Your genetic counselor will provide education on the potential benefits, harms, limitations, and outcomes of genetic testing and sharing the results with family
• If you move forward with a genetic test, your genetic counselor can help interpret the results and discuss management of screening or risk-reduction options with breast, ovarian, and other cancer specialists

If you’re ready to start looking or want to learn more, you can find a genetic counselor at https://www.nsgc.org.

Knowledge is power – and we can be powerful together

Your greatest asset in the fight against breast/ovarian cancer is knowledge – of both the scientific facts and your own biology. This includes being educated on HBOC and the intrinsic link between breast and ovarian cancer. If caught and treated early, ovarian cancer patients’ 5-year survival rate is 92%. However, only 20% of cases are actually diagnosed this early. We need to change this. Please share this article with friends and family members. Keep up with us on social media for helpful tips, inclusive events, and up-to-date facts.