4 Ways Your Genes Affect Breast Cancer Care

Expert answers to common genetics questions
genetic testing

With breast cancer being the most common cancer in American women besides skin cancer, there’s a good chance either you or someone in your family or close circle has been affected by this disease. 

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As we learn more about the genetics involved, we know more about the role of family history — and how to diagnose and treat patients based on their specific needs. Researcher Charis Eng, MD, PhD, explains four ways your genetics can affect your breast cancer care.

1. How has genetics changed the way surgeons approach breast cancer?

Understanding the genetic factors for risk of breast cancer has moved family history to the forefront of the conversations surgeons have with breast cancer patients. If your doctor finds that you’re at risk for hereditary breast cancer syndromes, they will refer you for genetic counseling

The American Cancer Society reports that about 5% to 10% of breast cancer cases are thought to be hereditary. 

“It made surgeons and other doctors watch out for red flags of hereditary cancer,” says Dr. Eng. “These red flags can be everything from a family history of cancer to a diagnosis at a young age to having cancer in both breasts. Family and personal history are more important now than ever.”

2. When in the process should I see my doctor?

If you felt a breast lump, had an abnormal mammogram, nipple discharge or had a breast needle biopsy done, you should schedule an appointment with your doctor, who will then identify if you’re at risk for a hereditary breast cancer syndrome.

Rarely, a patient with a known genetic mutation will be referred to their doctor from a geneticist — usually after someone else in his or her family has tested positive.

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“This team approach is important,” Dr. Eng says. “I always want to have a high-risk breast specialist involved when a genetic screening shows a mutation. This can be informative or actionable because it helps women make difficult treatment decisions.”

Frequently, genetic counseling is done immediately after an initial surgical consultation. Surgical plans — such as whether to undergo breast conservation (lumpectomy) or have a bilateral mastectomy — may hinge on genetic testing results. 

“It’s important to identify these high-risk patients early so we do not delay their care,” says Dr. Eng.

When thinking about genetic screening, consider these questions:

  • Will my insurance cover the cost if I can’t pay out of pocket?
  • Am I prepared for the results? Is my family prepared?
  • What will I do with this information once I get it?

3. Will my genetic screening results affect my treatment decisions?

Most commonly, patients with a hereditary breast cancer syndrome have a BRCA mutation, which equals to about a a 60% to 80% lifetime risk of breast cancer. 

“For these patients, we usually talk about bilateral mastectomy, although there are other options as well, such as increased surveillance,” Dr. Eng says.

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There are 10 genes that play a role in breast cancer and BRCA1 and BRCA2 are the most common genes and the ones most people know about. Mutated versions of BRCA1 and BRCA2 can lead to abnormal cell growth and possibly cancer. Right behind BRCA1 and BRCA2 is PTEN, and the type of genes also affects what types of cancers to watch for. 

“With PTEN, for example, we look for thyroid cancer and other cancers such as uterine and colon, as well as breast cancer,” says Dr. Eng. “Then there are much more rare genetic mutations such as CDH1, which is associated with lobular breast cancer, and NF1, which usually comes with skin changes in addition to the risk for breast cancer.”

If you have one of these rarer genetic syndromes, your doctor will have a conversation with the geneticist to discuss an individualized treatment plan for you.

4. What’s the next step after a positive genetic screening?

“Patients usually want to know their options and the risks with each option,” says Dr. Eng. “They also want to know the risks their family members may or may not have given this diagnosis.”

Your results can be confusing to understand, but your doctor will be able to map out everything you need to know. There are a variety of treatment options available if you receive a positive genetic screening and your doctor can discuss prophylactic surgery, reconstructive options and alternatives such as increased surveillance.

“Mostly, patients want to know what comes next,” says Dr. Eng. “Because of genetic screening — and because of the team approach that involves geneticists, surgeons, oncologists and others — we can give them as much information as possible to make the best decision for them.”

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