Cancer is a health condition that can occur due to changes in your genes. Genes carry instructions that tell the proteins in cells how to behave. Mutations in the BRCA1 and BRCA2 genes greatly increase your risk of developing breast cancer.
If you have a family history of breast cancer, you may be wondering about your chances of inheriting the condition.
Thanks to genetic research, this is a much easier question to answer. Researchers have identified mutations in two genes — BRCA1 and BRCA2 — as primary genetic causes of breast cancer.
Not everyone who gets breast cancer inherits it through their genes, and not everyone with mutations in their BRCA1 or BRCA2 genes will develop the condition. Still, having these specific mutations greatly increases your risk of developing breast cancer during your lifetime.
Let’s take a look at how these genetic mutations contribute to cancer, how you can find out if you have these mutations, and who may be a good candidate for genetic testing.
You’ll notice that the language used in this article to share stats and other data points is pretty binary, fluctuating between the use of “male” and “female” or “men” and “women.”
Although we typically avoid language like this, specificity is key when reporting on research participants and clinical findings.
The studies and surveys included didn’t report data on — or include —participants who were:
- transgender
- nonbinary
- gender nonconforming
- genderqueer
- agender
- genderless
When your genes cause proteins and cells to develop in atypical ways, cancer can develop. This can happen because of a gene mutation.
It’s possible to be born with certain gene mutations. This is called an inherited mutation. Scientists currently believe around 5–10% of breast cancers to be hereditary. Your genes may also mutate later in life due to environmental or other factors.
A few specific mutations can play a role in developing breast cancer. Affected genes tend to be those that control things like cell growth and the DNA in your reproductive organs and breast tissue.
The BRCA1 and BRCA2 genes typically make proteins that can repair your DNA when it gets damaged, particularly in your breasts and ovaries. When there are mutations in these genes, atypical cell growth can develop. These cells can then become cancerous.
About
People with these mutations also have an increased risk of developing other cancers, including:
Males who have the BRCA2 mutation have an increased risk of developing male breast cancer.
Your risk for having BRCA1 or BRCA2 mutations may be higher if you have:
- multiple family members who have had breast cancer
- relatives who developed breast cancer before they were 50 years old
- any family members who have had ovarian cancer
- any male relative who developed breast cancer
- any family members who developed both breast and ovarian cancer
- any family members who carry a BRCA gene mutation
In addition to BRCA1 and BRCA2, other genes can increase your risk of developing breast cancer if you inherit a mutation.
These genes include:
- CHEK2: Females with CHEK2 mutations have a 20–40% lifetime risk of breast cancer. This mutation is also linked to colorectal cancer and breast cancer in males.
- CDH1: Mutations in CDH1 put you at a
higher risk of developing hereditary diffuse stomach cancer (gastric cancer). This mutation also increases your risk of lobular breast cancer. - PALB2: This gene partners with the BRCA gene in your body. Females with mutations in the PALB2 gene have a 40–60% risk of developing breast cancer compared with 12.5% for the general population.
- PTEN: This is a gene that regulates cell growth. A PTEN mutation can cause Cowden syndrome, a condition that increases your risk of developing benign and cancerous tumors like those found in breast cancer.
- TP53: Mutations in TP53 can lead to Li-Fraumeni syndrome, a condition that predisposes your body to several different types of cancer, including breast cancer and brain tumors.
If you meet any of the criteria that increase your risk of having a cancer-related gene mutation, you may be considering genetic testing.
Testing for BRCA1 or BRCA2 mutations usually involves a simple blood or saliva test. A doctor or healthcare professional will draw a sample of your blood or saliva and send it to a lab. The lab technician looks for the mutations, and the doctor calls you with the results.
If you’re curious about other genetic mutations that you may have, you’ll need to speak with a doctor about getting tests for those mutations, too.
You can also pay a direct-to-consumer company to do the test without a referral from your doctor, but these tests only test for BRCA1 and BRCA2 gene mutations. They can’t rule out any and all factors that could increase your risk of breast cancer.
The
It’s important to note that insurance may not always cover genetic testing. Also, keep in mind that most breast and ovarian cancers have other causes and are not linked to these inherited mutations.
Genetic testing is
- a known BCRA1 or BCRA2 mutation in your family
- a strong family history of breast or ovarian cancer
- a moderate family history of breast or ovarian cancer and Ashkenazi or Eastern European Jewish ancestry
- a personal history of ovarian, fallopian tube, or peritoneal cancer
- a personal history of certain types of breast cancer
Experts
BRCA1 and BRCA2 are known as the “breast cancer genes,” but the genes themselves don’t increase your risk of breast cancer. Everyone has these genes, but people who have mutations in them can have an increased risk of breast cancer, ovarian cancer, and several other types of cancer.
For this reason, many people with a family history of breast cancer are getting genetic testing to see if they have the mutations. Having a mutation doesn’t necessarily mean you’ll develop breast cancer. Knowing your risk may make you feel more at ease, or it might make you anxious.
If you have a family history of breast cancer, you might want to speak with a doctor about the pros and cons of getting genetic testing for these mutations.