HER2-positive stands for human epidermal growth factor receptor 2. Cells in the body typically receive messages to grow and spread from receptors located on the outside of the cell. These receptors are sensitive to different enzymes, or messengers, that are produced in the body. The receptors regulate different cells and tell them what to do (i.e., grow, spread, or die).

These receptors are also on the outside of cancer cells. But, cancer cells may have a lot more receptors than a normal cell. This increased number, along with other changes around the cancer cell, allows them to receive more messages to grow and spread when compared to normal, noncancerous cells. We call these receptors “oncodrivers,” meaning they drive the cancer to grow.

In these cases, the cancer can be very dependent on those receptors to continue to grow and spread. When these receptors are blocked and not allowed to receive messages, the cell cannot grow or spread.

In HER2-positive breast cancer, the number of HER2-positive receptors on the outside of the cell is greater than it would be in a normal, noncancerous cell. This helps drive the cancer to grow and spread.

Your oncology team will determine if you need surgery and discuss which type of surgery is best for you. Many different factors go into deciding what type of surgery to undergo and when to have the surgery (either before or after systemic treatment). Your doctors will discuss your options with you in detail, and together, you can come to a decision.

Treatment options include radiation therapy, surgery, chemotherapy, and endocrine therapy. You’ll also have access to treatments that specifically target HER2 receptors.

Many factors determine the type and duration of treatment you’ll receive. These include your age, other health conditions, the stage of cancer, and your personal preferences. Your oncology team should discuss all the treatment options that are available for your specific case.

The goals of treatment depend on the stage of breast cancer you have at diagnosis. For those with stage 0 to 3 breast cancer, the goal of treatment is to cure the cancer and prevent future recurrence.

Stage 4 breast cancer means the cancer has spread beyond the breast and local lymph nodes. At this stage, the goal of treatment is to control the growth of the cancer and prevent any organ damage or pain.

Unfortunately, stage 4 breast cancer cannot be cured. But with the advent of new and innovative drugs, it’s possible to stay in a period of stable disease for long periods of time.

The outlook for HER2-positive breast cancer depends on a few different factors. This includes the stage of the cancer, your ability to tolerate treatments, your age, and your current health status.

The advent of many new and effective targeted drugs working in combination with other therapies continue to improve outlooks for women with HER2-positive breast cancer.

Treatment side effects will depend on the type of treatment you undergo. In general, patients can tolerate monoclonal antibodies used to target HER2-positive receptors well.

Some potential side effects include fatigue, joint pain, headache, and insomnia. A majority of these side effects are minor in severity.

Rarely, monoclonal antibodies used to treat HER2-positive breast cancer can cause a weakening of the heart muscles. Your oncology team will discuss this risk with you and monitor you closely for any signs of this rare complication.

In general, you should follow a healthy lifestyle after a breast cancer diagnosis. Stop smoking if you smoke, limit alcohol intake to one drink or less per day, and perform moderate exercise daily.

You should also follow a healthy diet that is high in fruits, vegetables, and low-fat proteins. Limit your intake of refined sugars and foods that are high in fat.

In patients with early-stage HER2-positive breast cancer (stages 0 to 3), the 10-year local relapse survival ranges from 79 to 95 percent. The range depends on the cancer stage at diagnosis and the type of surgery.

However, many factors can contribute to your personal risk of recurrence. Discuss your individual risk with your oncology team.

Advice offered by Hope Qamoos, nurse practitioner in women’s health. Hope has over 15 years of experience working in women’s health and oncology. She has spent her professional career working with key opinion leaders in the field at university hospitals such as Stanford, Northwestern, and Loyola. In addition, Hope works with a multidisciplinary team with the goal of improving the care of women with cancer in Nigeria.