There are various kinds of breast cancer, and the type you’re diagnosed with can influence your prognosis and the treatments that might be most beneficial to you.
Breast cancers are typically identified by the part of the breast where the cancer cells first appear, such as invasive ductal carcinoma or invasive lobular carcinoma, but some cancers are further differentiated by whether they’re fueled by naturally occurring hormones or proteins.
The presence or absence of such hormones can greatly inform the treatments the breast cancer experts at the OSUCCC – James may recommend for you. For example, if there’s an excess of the human epidermal growth factor receptor 2 (HER2), we can target that protein to stop or slow the growth of the tumor.
What is HER2-positive breast cancer?
Diseased breast cells have receptors that can be sensitive to specific hormones that cause them to grow. Breast cancers are typically described by the presence or absence of these three cell receptors:
- Estrogen receptors (ER)
- Progesterone receptors (PR)
- HER2
After cancer cells are removed from the breast during biopsy or surgery, they are tested for these hormone receptors and the amount of the HER2 protein or receptor. If the cancer is sensitive to estrogen or progesterone, the cancer is called hormone-positive breast cancer (also known as endocrine-positive).
If the tumor has a higher level of the HER2 protein expressed on its surface, it’s considered HER2-positive breast cancer. Between 15% to 20% of all breast cancers are HER2 positive. It can spread rapidly and has a higher incidence of recurrence than some other breast cancer types.
HER2-positive breast cancer can test positive for all three receptors (triple-positive) or negative for the ER and PR but positive for HER2.
HER2-positive breast cancer symptoms
HER2-positive breast cancer has similar symptoms to other types of breast cancer. Some of these symptoms can be difficult to tell apart from symptoms of other common conditions, such as hormonal changes. Some potential signs of breast cancer can include:
- A new or growing breast lump
- Swelling or changes in breast size or shape
- Breast or nipple pain
- Nipple discharge
- Nipple inversion or turning in of the nipple
- Thickening of breast or nipple skin
Remember, many of these symptoms may not appear at all or until later stages of breast cancer, and the best way to catch the condition early is to have regular mammograms. If you’re experiencing any of these symptoms, schedule your mammogram today.
Diagnosing HER2-positive breast cancer
HER2-positive breast cancer is most often discovered through a physical examination or a mammogram. You might need other tests to identify or confirm a diagnosis. Those diagnostic tools include:
- Diagnostic mammogram – Used to investigate suspicious areas or abnormal screening results, this type of mammogram involves X-rays of different angles, magnification views and sometimes breast tomosynthesis, also known as a 3D mammogram.
- Ultrasound – This uses sound waves to examine the breast tissue and other characteristics of the breast.
- Magnetic resonance imaging (MRI) – An MRI of the breast can be especially useful for examining people with an elevated risk for breast cancer.
- Biopsy – If a suspicious area is detected, we’ll take a sample of that breast tissue for trained pathologists to examine under a microscope for signs of abnormal cells. This test can confirm or rule out cancer as well as give us key information about the cancer, if it’s diagnosed.
If cancer is confirmed after biopsy, several more tests will be done on the tissue to determine the amount of HER2 protein present. Those tests include:
- Immunohistochemistry (IHC) test
- Florescent in situ hybridization (FISH) test
The tissue sample will also be tested for hormone receptors at this time.
HER2-positive breast cancer treatment
Though HER2-positive breast cancer can grow quickly and has a greater chance of spreading to other parts of the body (metastasize) or recurring, treatments can be quite effective.
Typically, several methods of treatment are combined to best attack a cancer that is HER2-positive. Our customized treatment plans will consider the size of the tumor and whether the cancer has spread to the lymph nodes or beyond to other parts of the body.
Treatment for earlier stages of HER2-positive breast cancer
If the tumor is less than 2 centimeters and hasn’t spread, we might recommend:
- Surgery – A lumpectomy or mastectomy will first be performed to remove the tumor and breast tissue.
- Chemotherapy – This is typically given after the surgery to make sure the cancer doesn’t return; however, it can be given before the surgery to shrink the tumor.
- Targeted therapy – A medication called trastuzumab (Herceptin) targets the HER2 protein directly.
- Radiation therapy – Depending on certain characteristics of the cancer, this might be recommended following surgery.
- Endocrine (hormone) therapy – If the breast cancer is also sensitive to progesterone or estrogen, medications that affect how hormones are made or how your body reacts to the hormones can be given.
Treatment for later stages of HER2-positive breast cancer
If the tumor is larger than 2 centimeters or the cancer has spread to nearby lymph nodes, we might recommend:
- Chemotherapy – Typically, one or two types of chemotherapy will be started soon after diagnosis and prior to surgery (neoadjuvant).
- Targeted therapy – In combination with the chemotherapy, two antibodies (trastuzumab and pertuzumab) that target the HER2 receptor are given.
- Surgery – After chemotherapy, a lumpectomy or mastectomy is done to remove the remaining cancer cells.
Depending on characteristics of the cancer, radiation might be recommended. If you have hormone-positive breast cancer, hormone therapy can be beneficial to your treatment plan.
Related Resources
Breast Cancer Risk Factors and PreventionBreast Cancer Symptoms and Causes
Breast Cancer Diagnosis and Staging
Breast Cancer Treatment