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How gene mutations affect your breast cancer odds

breast cancer gene mutations

It’s not a guarantee that if someone is diagnosed with breast cancer that they inherited it from a family member. However, in the cases where there is a genetic link, understanding the genetics behind a breast cancer diagnosis can help someone get better treatment and can make it more clear what type of risk their loved ones have for also being diagnosed. If someone has yet to be diagnosed, then genetic testing for certain gene mutations can help them understand how at risk they are for breast cancer.

If you have a family history of breast cancer, you may be wondering what your chances are of inheriting the condition. Gene mutations can cause breast cancer, and mutations in the BRCA1 and BRCA2 genes are a primary genetic cause of breast cancer.

Again—just because someone is diagnosed with breast cancer doesn’t mean their diagnosis is related to their family history and even if someone has mutations in their BRCA1 or BRCA2 genes that isn’t a guarantee they will experience a breast cancer diagnosis. That being said, these mutations do greatly increase the risk of developing breast cancer and whether or not you’ve already been diagnosed with breast cancer it’s worth knowing how these genetic mutations contribute to cancer.

Keep reading for more insight into what your DNA can tell you about your cancer, how to find out if you have one of these mutations, and if you’re a good candidate for genetic testing.

How Certain Genes Affect Breast Cancer

One potential cause of cancer is a change to your genes. Essentially, genes carry instructions for the proteins in cells that tell them how to behave. If a gene mutation makes proteins and cells develop in normal ways then cancer can develop in the body.

Some people are born with gene mutations—known as an inherited mutation—and other people experience gene mutations later on in life as a result of environment or other factors. It’s believed that between 5 and 10 percent of breast cancer diagnoses are caused by hereditary gene mutations.

While not every gene mutation that can cause breast cancer to develop is known, it’s most common for mutations surrounding the genes that control cell growth and the DNA in your reproductive organs and breast tissue to lead to breast cancer.

BRCA Genes

BRCA genes are quite well known thanks to renowned actress Angelina Jolie’s activism regarding spreading awareness of these genes and her aggressive preventative treatment due to her carrying the BRCA1 gene mutation.

Both the BRCA1 and BRCA2 genes tend to make proteins that are capable of repairing damaged DNA with a main focus on the DNA in the ovaries and breasts. Once mutation occurs with these genes it can cause abnormal cell growth and those cells have the potential to become cancerous.

According to the Centers for Disease Control and Prevention (CDC) it’s estimated that 50 out of every 100 women born with a BRCA gene mutation will develop breast cancer by the time they turn 70 years old. Women with a BRCA gene mutation are also at a greater risk of developing other cancers like melanoma, colon cancer, pancreatic cancer, and ovarian cancer. Men who have the BRCA2 mutation also have an increased risk of developing male breast cancer.

Certain factors put those who have BRCA1 or BRCA2 mutations mutations at a higher risk for developing breast cancer, such as having:

  • Multiple family members diagnosed with breast cancer
  • A relative who developed breast cancer before 50
  • family member diagnosed with ovarian cancer
  • A male relative who developed breast cancer
  • Someone in the family who developed both breast and ovarian cancer
  • Someone in the family who was found to carry a BRCA gene mutation


Other Genes That Increase Risk of Breast Cancer

Alongside the BRCA genes, there are other genes that can increase the risk of developing breast cancer if someone inherits a mutation.

  • CDH1. Mutations for this gene place you at a higher risk of developing hereditary diffuse stomach cancer (gastric cancer) and lobular breast cancer.
  • PALB2. The PALB2 gene works with the BRCA gene in your body, so if someone has a PALB2 mutation they are 9.47 times more likely to develop breast cancer.
  • PTEN. This gene regulates cell growth and A PTEN mutation can cause Cowden syndrome, which is a condition that increases the risk of developing benign and cancerous tumors (such as those found in breast cancer).
  • TP53. TP53 mutations can cause Li-Fraumeni syndrome, a condition which can make your body more susceptible to brain tumors and several different types of cancer—including breast cancer.


Why Genetic Testing Matters

If someone meets any of the aforementioned criteria for being at a higher risk for the BRCA1 or BRCA2 mutations, then they should seriously consider pursuing genetic testing. These tests are simple and typically only require a saliva or blood test which will be sent for a lab to look for the mutations. It’s possible to get a prescription from a doctor to do this or to pay a direct-to-consumer company to do the test—which doesn’t require a prescription. While these tests can’t rule out all factors that can increase the risks of breast cancer, they can help you identify BRCA related risks. Your doctor can also help you identify other genetic mutations that you may be at risk for and can help you arrange for testing.

To help make it easier for Outcomes4Me users to obtain genetic testing, we partnered with Invitae—a leading medical genetics company—to expand education and access to genetic testing to breast cancer patients and survivors. This collaboration leverages the strengths of Invitae, which supplies clinical grade genetic testing, and Outcomes4Me’s 360-degree, validated and evidence-based cancer support and treatment options via our free and easy-to-use app. Patients can now receive genetic counseling through Invitae’s partnership with Genome Medical, get testing, and upload their results within the Outcomes4Me app.

Learn more about our partnership with Invitae today!

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