Breast Cancer: Know Your Family History

For some patients, the risk of developing breast cancer is in their genes. About 5 percent to 10 percent of breast cancers are hereditary — primarily caused by genetic mutations inherited from either a mother or father.

Genetic testing for these mutations has been available for more than a decade. “Testing can be scary but for high-risk patients it is important,” said genetic educator Rae Wruble, R.N. “The results can tell us someone’s risk for cancer and guide us toward appropriate action, such as surgery and medical management.”

Other risk factors include having a first-degree relative (mother, sister or daughter) with breast cancer, being diagnosed with breast cancer at age 50 or younger, having three or more relatives on the same side of the family with breast cancer at any age, having male breast cancer and being diagnosed with ovarian cancer at any age.

“Patients need to discuss their family histories with their doctor,” said Cristina Lopez Peñalver, M.D. “By understanding risks, patients can make informed decisions about how to detect potential cancer. Knowledge is power.”

For that 5-10 percent of patients whose breast cancer risk is higher because of genetic factors, here are some facts about genetic risk:

The most common cause of hereditary breast cancer is an inherited mutation in the BRCA1 or BRCA2 gene.

Although in some families with BRCA1 mutations the lifetime risk of breast cancer is as high as 80 percent, on average the risk ranges between 55 percent to 65 percent. For BRCA2 mutations the risk is lower, around 45 percent.

Breast cancers linked to these mutations occur more often in younger women.

Women with these inherited mutations also have an increased risk for developing other cancers, particularly ovarian cancer.

In the United States, BRCA mutations are more common in Jewish people of Ashkenazi (Eastern Europe) origin than in other racial and ethnic groups, but they can occur in anyone.

Other gene mutations can also lead to inherited breast cancers. These gene mutations are much rarer and often do not increase the risk of breast cancer as much as the BRCA genes. 

 Who Should Consider Genetic Testing?

Breast cancer diagnosed before age 50

Cancer in both breasts

Both breast and ovarian cancers

Multiple breast cancers

Two or more primary types of BRCA1- or BRCA2-related cancers in a single-family member.

Cases of male breast cancer

Ashkenazi Jewish identity

If you are concerned about your risk of developing breast or ovarian cancer, contact the Baptist Health Breast Center’s Genetic Risk Education Service ^[1] at 786-662-4761 for more information or to schedule an appointment.

 Source: American Cancer Society and National Cancer Institute