• Human epidermal growth factor receptor 2 (HER2)-positive breast cancer has a higher risk of recurrence, or coming back, especially within five years of the diagnosis.
• Certain factors increase your risk of HER2-positive breast cancer recurrence, including lymph node involvement, larger tumor size, and diagnosis at age 50 or younger.
• It’s not always possible to prevent HER2-positive breast cancer recurrence, but regular follow-ups may help catch it earlier, and it can be treated.

You may have heard that if breast cancer returns, it’s most likely to happen within the first five to 10 years after treatment. It’s natural to worry about your breast cancer returning after treatment. If you’re like other MyBCTeam members, you’ll want more information.

One MyBCTeam member shared, “I’m constantly wondering if the cancer will recur.” Another member commented, “I try not to worry about recurrence, but the thoughts pop up in my mind.”

Breast cancer recurrence is when breast cancer comes back after you complete treatment.

If you’ve been diagnosed with HER2-positive breast cancer, a fast-growing and aggressive type, you might worry more about it coming back. This is because HER2-positive breast cancer has a higher risk of recurrence compared to other types of breast cancer. HER2-positive breast cancer is also associated with early recurrence within five years of being diagnosed.

Continue reading to learn more about HER2-positive breast cancer recurrence.

How Do You Know if You Have HER2-Positive Breast Cancer?

Your healthcare provider will likely test your breast cancer cells for HER2 when you have a biopsy or when your tumor is removed during surgery. A breast biopsy is a medical procedure where a small sample of breast tissue is taken using a special needle or during surgery. A pathologist examines the sample under a microscope to check for cancerous cells and determine HER2 status.

“I try not to worry about recurrence, but the thoughts pop up in my mind.”

— A MyBCTeam member

You can learn more about testing for HER2 here.

If your breast cancer cells have higher-than-normal levels of the HER2 protein, it’s known as HER2-positive breast cancer. Your cancer may be considered HER2-negative even if you have some HER2 protein in your cells. Talk to your cancer care team about your HER2 results.

The HER2 protein is a receptor that helps regulate how your healthy breast cells grow and divide. However, about 10 percent to 20 percent of people with breast cancer have a change in the HER2 gene that causes breast cancer cells to make more HER2 protein. When breast cancer cells have excess HER2 protein, they grow and divide abnormally or without proper control.

It’s important to know your HER2 status because it can affect the type of treatment you receive. Your HER2 status also influences your risk of metastasis (cancer spreading) and recurrence.

What Is Breast Cancer Recurrence?

Breast cancer recurrence is when breast cancer comes back after you complete treatment. You may have a recurrence if your first treatment didn’t kill all of the cancer cells in your breast. The cancer cells that remain after breast cancer treatment may be dormant (inactive) for several years before they become activated to begin growing and spreading again. HER2-positive breast cancer has a recurrence peak of around 20 months. This means the chance of recurrence is highest about 20 months after the first diagnosis or after finishing the main treatment.

There are three types of breast cancer recurrence:

• Local — Cancer comes back in the same area as the original tumor.
• Regional — Cancer comes back in the lymph nodes near the original tumor (such as the armpit or collarbone area).
• Distant — Cancer spreads to an area far from the original tumor, also known as metastatic breast cancer. This type of breast cancer may affect the brain, bones, or lungs.

If you develop cancer in the breast that hasn’t been previously treated for breast cancer, it’s not considered a recurrence. Instead, this is a new cancer or secondary cancer.

Symptoms

Your symptoms depend on the type of breast cancer recurrence. If you have a local recurrence, you may notice:

• Lumps on your breast or chest
• Changes in your nipple
• Skin changes near the lumpectomy site or the surgical scar
• Firm breast tissue

If you have a regional recurrence, you may notice:

• Chest pain
• Trouble swallowing food or drinks
• Arm or shoulder pain
• Swollen lymph nodes in the area around your armpit or collarbone

• Swollen arm

The symptoms of a distant recurrence depend on where the cancer has spread and may include:

• Pain
• Cough
• Headaches
• Dizziness
• Fatigue (extreme tiredness that doesn’t improve with sleep)
• Weight loss
• Weakness

Read more about early symptoms and signs of HER2-positive breast cancer.

Diagnosis

If you experience symptoms of breast cancer recurrence, talk to your cancer care team right away. Breast cancer recurrence is diagnosed with many of the same tests you had during your original diagnosis, such as imaging tests, blood tests, and biopsy.

What Are the Risk Factors for Breast Cancer Recurrence?

Some people with breast cancer have a higher risk of breast cancer recurrence, including people diagnosed with:

• Breast cancer before age 35
• Stage 3 breast cancer
• Triple-negative breast cancer or inflammatory breast cancer

After targeted therapy, about 25 percent of people with HER2-positive breast cancer experience a recurrence within 10 years.

Studies have also looked at the risk of recurrence, specifically for people with early-stage HER2-positive breast cancer. Researchers found that recurrence rates of HER2-positive breast cancer were highest among people with the following characteristics:

• Active cancer cells after undergoing neoadjuvant therapy (treatment before surgery)
• Lymph node involvement
• Age 50 or younger when diagnosed
• Large tumor size
• A high body mass index (BMI)
• Hormone receptor-positive status

Talk to your oncology care team about your risk factors for the recurrence of HER2-positive breast cancer.

When Is HER2-Positive Breast Cancer Most Likely To Recur?

HER2-positive breast cancer is associated with early recurrence within five years of being diagnosed. A 2023 study found that most HER2-positive breast cancer recurrences occur within five years of the original diagnosis.

Your hormone receptor (HR) status also influences the time to recurrence. The previously mentioned study found that 75 percent of recurrences occurred within 3.05 years for people with HER2-positive, HR-positive breast cancer.

How Is HER2-Positive Breast Cancer Recurrence Treated?

Your treatment options for breast cancer recurrence depend on the type of recurrence, prior treatments, and your breast cancer subtype.

Surgery and Radiation Therapy

Local and regional recurrence may be treated with surgery. If you have a local recurrence, treatment may include a mastectomy (if you originally had breast-conserving surgery) or removal of the tumor. The affected lymph nodes may be surgically removed if you have a regional recurrence. Surgery may also be helpful in some cases of distant recurrence. Radiation therapy may be given before or after surgery for any type of recurrence, as well.

Systemic Therapies

Systemic therapies are drug treatments that affect your whole body. HER2-positive breast cancer is often treated with drugs that specifically target HER2, including:

• Ado-trastuzumab emtansine (Kadcyla)
• Fam-trastuzumab deruxtecan-nxki (Enhertu)
• Lapatinib (Tykerb)
• Margetuximab-cmkb (Margenza)
• Neratinib (Nerlynx)
• Pertuzumab (Perjeta)
• Trastuzumab (Herceptin)
• Trastuzumab, pertuzumab, and hyaluronidase-zzxf injection (Phesgo)
• Tucatinib (Tukysa)

HER2-positive targeted therapy may be combined with other treatment regimens, such as chemotherapy, hormone therapy (also called endocrine therapy), and immunotherapy. Talk to your cancer care team about the best treatment option for you.

Can You Prevent Breast Cancer Recurrence?

Researchers don’t know why breast cancer comes back in some people and not in others. Breast cancer treatments can help reduce your risk of recurrence. The prediction of recurrence in this type of cancer is still under study, but advancements in treatment are promising.

Before targeted therapies for HER2-positive breast cancer, the risk of recurrence within 10 years after treatment was between 30 percent and 50 percent. With targeted therapy, about 25 percent of people with HER2-positive breast cancer experience a recurrence within 10 years.

Other treatments, such as chemotherapy and hormone therapy, can also help reduce your recurrence risk. Many people with hormone-positive breast cancer are advised to take maintenance therapy for five to 10 years after other treatments are complete. Talk to your cancer care team about the best treatments to help you lower your risk of HER2-positive breast cancer recurrence.

It may not be possible to prevent breast cancer recurrence. However, regular follow-ups with your cancer care team and breast self-exams can help you discover a breast cancer recurrence before it spreads and when it’s easier to treat.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 77,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Do you have HER2-positive breast cancer? Are you worried about recurrence? Share your experiences in the comments below, start a conversation by posting on your Activities page, or connect with like-minded members in Groups.