4 things to know about genetic testing for breast cancer

Breast cancer is often thought to run in families, but only about 10% of cases are caused by inherited genes. About one in eight women will get breast cancer in their lifetime, even if they don’t have a genetic mutation, though having one can raise the risk. If you have a family history of cancer, especially breast cancer, it can be a genetic mutation or change inherited from a parent. Now, knowing your genetic risk can even be a way to help protect future generations to come. 

Maggie Ward, DNP, APRN, AGCNS-BC, OCN, a board-certified genetics practitioner at Ascension Via Christi in Wichita, Kansas, shares 4 things you should know about genetic testing that can affect you or your family members chances of breast cancer in the future: 

Understanding genes and their mutations

Like many physical traits inherited from your parents, genetic mutations are another unseen quality passed down to you. 

Genes act as instructions for our body’s cells. When there is a mutation present, it can cause cells to act differently than expected. 

When it comes to your health, some changes don’t cause harm. When a gene may cause harm to you, through cancer or other health issues, it is a gene mutation. If it is passed through to you from your parents, like the commonly known BRCA gene mutation, it is an inherited gene mutation. 

Some genes can change over time because we age or are exposed to factors that can cause a change. This is called a somatic alteration, which happens inside a cell or cells. It is not with you at birth and can’t be passed to your children. 

How can I tell if I have a gene mutation?

It is thought that breast cancer is often something in the family, but gene inheritance is only responsible for up to 10% of breast cancers. With breast cancer, in particular, it is estimated that one in eight women will develop breast cancer in their lifetime, regardless of the presence of a genetic mutation. However, with a genetic mutation present, that risk can be higher. It is important to note that even if a person carries a genetic mutation with an increased risk for cancer, it does not guarantee that a cancer will develop. There are factors your care team can evaluate to help you understand your risk.

With info about you and your family’s health history, providers like Maggie Ward can help you determine the type of genetic test that is a best fit for you. 

A gene mutation may be present if you or a family member: 

• Received a breast cancer diagnosis at the age of 50 or younger
• Were diagnosed with two different primary breast cancers 
• Has or had ovarian, pancreatic and/or high-risk prostate cancer
• Has or had more than two immediate blood relatives diagnosed with breast cancer at any time
• Has a known breast cancer mutation in your family
• Are of Ashkenazi Jewish heritage 

Most people know about the BRCA gene mutations, so we can use this as an example to evaluate a person’s risk of developing breast cancer. If you have a BRCA1 or BRCA2 gene mutation, it can mean you’ll have up to a 7 in 10 chance of getting breast cancer by age 80. This increases if you have multiple family members who have had breast cancer. You’re more likely to be diagnosed younger, and have cancer in both breasts. You also have a higher risk of ovarian, pancreatic or other cancers. 

For your family and future generations, genetic testing can help save their lives and better understand how sooner evaluation and intervention could be lifesaving. 

Gene mutations that are linked to breast cancer

BRCA1 and BRCA2, which stands for BReast CAncer gene, are the most commonly known mutations. Other cancer-causing mutations can include: 

• PALB2 - Studies have shown women can be more than 50% likely to have breast cancer by 80. It also increases both men and women's risk for pancreatic cancer. 
• CHEK2 - This mutation varies and depends on the location of the gene error. It can increase colon and prostate cancer risk, and breast in certain patients.
• ATM - Some research shows this could potentially double the average risk of breast cancer. 
• STK11 - Causes PeutzJeghers syndrome, which can cause people to have hamartomatous polyps in the small intestine, colon and stomach. It raises the risk of gastrointestinal, breast, lung cancers and tumors in the ovaries. 
• CDH1 (linked with hereditary diffuse gastric cancer) - Increases the risk of gastric cancer, and raises breast cancer risk in women. 
• PTEN (linked with Cowden syndrome) - Increases risk of benign and cancerous tumors in the breast and growths in other organs like thyroid, uterus, ovaries and the digestive tract.
• TP53 (linked with Li-Fraumeni syndrome) - This can cause cancers as young as childhood, which mostly results in breast cancer, as well as soft tissue cancer, adrenal gland cancer, leukemia and brain cancer
• BARD1 - Breast cancer, commonly triple-negative breast cancer. 
• RAD51C and RAD41D - Breast cancer, commonly triple-negative breast cancer. 

What test should I do for genetic mutations? 

While there are many different models of tests available, there are two that are available online and commonly used by providers. 

The most common and available evaluation is the Breast Cancer Risk Assessment Tool, also called the BCRAT or Gail Model. This can help determine your risk for invasive breast cancers. It uses your medical, reproductive, and breast cancer history among first-degree relatives, like sisters, daughters or mothers. 

Another test is the Tyrer-Cuzick model (IBIS). It is considered more accurate, especially when factoring in breast density, genetics, and specific family history details. It provides a score with all of your personal and family health history and helps categorize what level of risk you might be. 

While these tests can be useful for understanding your risk, don’t forget to talk to your doctor about further evaluation if you think you may be at risk for breast cancer. Getting your genetic testing done and working with a care team that can help coordinate your care, like our Via Christi Cancer Outreach and Risk Assessment program, can help provide peace of mind in your journey.” 

To learn more about Via Christi’s Cancer Outreach and Risk Assessment and Genetic Testing in Wichita, Kansas, call 316-268-5890. To learn more about services in Manhattan, Kansas, call 785-776-2813.

This blog is intended for general informational use. Any health-related information shared is not meant to provide or replace professional medical advice and does not establish a patient-provider relationship. If you are experiencing a medical emergency, call 911 or go to the nearest emergency room.