Is breast cancer genetic?

Families pass down many things: traditions, names, heirlooms, recipes. But if you have family members who have or had breast cancer, you might wonder if that, too, can be inherited.

Read on for answers to some common questions about having a family history of breast cancer.

Does breast cancer run in families?

Yes, breast cancer can be hereditary. This means it runs in families and can be passed down genetically. 

A family history of cancer means that a first-degree blood relative — such as a parent, sibling, or child — or second-degree relative — such as an aunt, uncle, grandparent, or half-sibling — has had breast cancer or another type of cancer.

According to the Centers for Disease Control and Prevention (CDC), about 5% to 10% of breast cancers are hereditary; these can be caused by genetic mutations. Genetic mutations are differences in genes that impact the way they function.

What types of breast cancer are caused by genetic mutations?

Any type of breast cancer can be caused by a genetic mutation that is passed down. 

Some of the genetic mutations that can lead to breast cancers include:

BRCA1 and BRCA2

Mutations to the BRCA1 or BRCA2 genes are called Hereditary Breast and Ovarian Cancer Syndrome; this is the No. 1 cause of inherited breast cancer. BRCA1 and BRCA2 genes help restore DNA and protect the body from cancer. Both men and women can have these mutations. The CDC writes that 7% of women in the United States will develop breast cancer by age 70. However, for women with BRCA1 or BRCA2 mutations, that number jumps to 50%.

PALB2 

Like the BRCA1 and BRCA2 genes, PALB2 genes protect the body from cancer by helping to repair damaged DNA.

CHEK2

CHEK2 genes are tumor suppressor genes. This means they play a role in stopping tumor growth, such as breast cancer.

CDH1 

CDH1 genes are also tumor suppressor genes. The CDH1 genes protect against cancer types including breast cancer, ovarian cancer, prostate cancer, pancreatic cancer and stomach cancer.

PTEN

PTEN is another tumor suppressor gene. Cowden syndrome, a hereditary cancer syndrome linked to an increased risk of breast and other cancers, is thought to be related to PTEN gene mutations.

TP53 

Mutations to the TP53 genes can increase the risk of certain cancers, including breast cancer. Li-Fraumeni syndrome is a rare hereditary cancer syndrome that increases the risk of soft tissue sarcomas, breast cancer, leukemia, lung cancer, brain tumors and adrenal cancer. Many people with Li-Fraumeni syndrome have TP53 gene mutations.

What should I do if someone in my family has breast cancer?

If you have a family history of breast cancer, let your doctor know.

From there, they can determine whether you are a candidate for genetic counseling and genetic testing. This evaluation is usually done starting at age 18. 

Regardless of whether you have a family history, you should practice breast awareness. This means noticing any changes to the way your breasts look and feel.

These changes might include:

• color
• hardness 
• skin thickness
• bumps
• swelling

If you have any changes that don’t go away, be sure to tell your doctor. 

Can men inherit breast cancer?

While breast cancer is more common in females, men can also get breast cancer.

Family history is a risk factor for male breast cancer. Men with a first-degree blood relative who has or had breast cancer have double the risk of breast cancer.

Men should practice breast awareness and tell their doctor about any changes to the way their chest looks or feels. 

When should I start getting mammograms if I have a family history of breast cancer?

Current guidelines recommend that average-risk women, or those without a family history of breast cancer, begin receiving:

• clinical breast exams at age 25  
• annual mammograms and clinical breast exams at age 40

If you have a family history of breast cancer, you should get evaluated by a doctor to see when it's appropriate to start breast cancer screenings. They may recommend that you begin screenings earlier than someone at average risk of breast cancer.

What age is hereditary breast cancer typically diagnosed?

Different types of breast cancer are typically diagnosed at different ages. That means there is no specific age that all hereditary breast cancers are typically diagnosed. 

However, in general, hereditary breast cancer caused by a genetic mutation is often early onset. This means it is diagnosed earlier than the average age of diagnosis for that specific type of breast cancer.

What are my options if I have a family history of breast cancer?

People with an increased risk of breast cancer have risk reduction options that can range from increased surveillance to risk reductive surgery.

Talk to your doctor to learn more about how to manage your risk of breast cancer. 

Request an appointment at MD Anderson online or call 1-877-632-6789.