Understanding HR+ or HER2– breast cancer diagnosis

What is HR+/HER2– breast cancer?

HR+/HER2- is the most common type of breast cancer, accounting for an estimated 69% of female breast cancer cases between 2016 and 2020.

Breast cancer cell tests can produce positive or negative results for two key factors:

HR

This represents hormone receptors, which are protein molecules on or inside a cell that bind to a hormone and allow that hormone to change the cell. For breast cancer, there are estrogen receptors (ER) and progesterone receptors (PgR). If breast cancer is HR+, one or both receptors are present. This means the hormone or hormones can affect the cell.

HER2

This represents human epidermal growth factor receptor 2, a protein that increases the rate at which breast cancer cells grow. HER2+ breast cancer is more aggressive and grows faster than HER2- breast cancer.

The Surveillance, Epidemiology, and End Results (SEER) Program categorizes breast cancer as follows:

What are the treatment options?

There are several treatment options for HR+/HER2- breast cancer. A person’s cancer stage and overall health can affect treatment decisions.

Surgery

Doctors use breast cancer surgery for different reasons, such as:

• to remove primary tumors
• to check lymph nodes for cancer cells
• to remove recurring cancer
• to reconstruct the breast

Types of breast cancer surgery include:

• partial breast removal (lumpectomy)
• complete breast removal (mastectomy)
• lymph node biopsy
• breast reconstruction

Radiation therapy

Radiation therapy targets specific areas of the body with high energy rays that can destroy cancer cells.

Breast cancer radiation therapy can help in several ways:

• to reduce the size of a tumor prior to surgery (neoadjuvant therapy)
• to reduce the chance of a cancer recurrence (adjuvant therapy)
• to treat a local recurrence
• to ease symptoms such as pain of advanced breast cancer (palliative therapy)

Doctors consider factors such as a person’s age, the nature of their cancer, and their medical history, including co-occurring conditions, to determine whether radiation therapy is appropriate.

Chemotherapy

Chemotherapy is medication that destroys or slows the growth of rapidly growing cells such as cancer cells.

As chemotherapy does not target specific cells, it can also harm healthy fast-growing cells such as those of the intestines, inside the mouth, and of a person’s hair. Side effects such as hair loss and mouth sores resolve after a person has finished chemotherapy.

Doctors prescribe chemotherapy to treat cancer and to reduce cancer symptoms.

Chemotherapy can:

• reduce the size of a tumor prior to surgery or radiation therapy (neoadjuvant therapy)
• destroy cancer cells that remain after radiation therapy or surgery (adjuvant therapy)
• increase the efficacy of other treatments
• treat cancer recurrences or metastases

The benefit of chemotherapy is not as clear for HR+/HER2- breast cancer as it is for other cancers. HR+/HER2- breast cancer often responds well to hormone-targeting treatments, with or without chemotherapy.

A 2023 study involving 15,271 females with HR+/HER2- invasive lobular cancer (ILC) found no added survival benefit of chemotherapy preceding endocrine therapy (ET) when compared to ET treatment alone.

Gene panel testing can help doctors decide whether a person with HR+/HER2- might benefit from chemotherapy.

Sometimes, oncologists use chemotherapy for metastatic HR+/HER2- cancer that has not responded to ET. A 2020 study examining treatments for HR+/HER2- breast cancer found that the chemotherapy medication capecitabine was effective after cancer progression on ET.

Endocrine hormone therapy

Also known as hormone therapy, hormonal therapy, or ET, this treatment works by interfering with the action of hormones that fuel the growth of hormone-sensitive tumors.

People with HR+/HER2- breast cancer often receive ET treatment due to this cancer’s hormone-positive status.

Strategies to target hormones include:

• surgery, radiation, or medication to prevent the ovaries from producing estrogen
• medication to stop the ovaries and other tissue from producing estrogen
• medication to block estrogen’s effects on breast cancer cells

Oncologists use hormone therapy in three ways:

• As adjuvant therapy to prevent a recurrence after early stage estrogen receptor (ER)+ breast cancer surgery.
• To treat metastatic or advanced ER+ breast cancer.
• As neoadjuvant therapy to reduce the size of an HR+ tumor prior to surgery. However, this is not a standard practice in the United States but is sometimes an option.

Hormone therapy may even be a preventive measure for people who have a higher risk of developing breast cancer. This is because most breast cancers are ER+.

Targeted therapy

Also known as molecular targeted therapy, targeted drug therapy uses medications that target specific molecules on or inside cancer cells to stop their growth and spread.

Doctors use this approach in certain situations. They would sometimes combine this with hormonal therapies, such as the first example in the chart below.

Examples of targeted therapy include:

Since targeted drug therapy does not typically damage healthy cells, it may have fewer side effects than chemotherapy or radiation therapy.

What is the outlook?

According to SEER, the 5-year relative survival for HR+/HER2- is 94.8%.

By SEER combined summary stage, the 5-year relative survival for HR+/HER2- is as follows:

Research from 2023 shows that HR+/HER2- breast cancer often has long survival rates, even when metastasized.

Living well with a diagnosis of HR+/HER2-

People living with cancer often experience stress along with the discomfort of side effects, both from the disease itself and its treatment.

Self-care strategies may help a person manage stress.

Examples include:

• extra rest
• a consistent sleep schedule
• relaxing hobbies, such as reading or listening to music
• mindfulness activities, such as meditation, yoga, or breathing exercises
• supportive social connections
• gentle exercise
• nutritious food

Using available work accommodations and accepting help from family and friends can also help, as well as learning to say no and set boundaries to conserve energy and manage stress.

Finding support

Receiving a diagnosis of breast cancer can feel overwhelming and frightening. Finding support can help ease this experience.

Options a person can try include:

• asking a doctor about breast cancer resources
• searching online for communities and support groups
• exploring online resources such as those by the American Cancer Society (ACS), Cancer Care, and the National Breast Cancer Foundation

Using internet searches, social media, and in-person or telephone queries are all ways a person can find breast cancer support.

Summary

HR+/HER2- is the most common type of breast cancer. Several treatment options are available. It is important to consider a person’s cancer stage and overall health before making a treatment decision.

HR+/HER2- breast cancer often has long survival rates. With proper treatment, along with support, stress-management, and self-care strategies, a person with this type of breast cancer can live a full life.