- What Is It?
- Survival Rate
HER2 (Human Epidermal growth factor Receptor-2) -positive breast cancers tend to be more aggressive and grow more quickly than HER2-negative cancers. HER2-positive cancers also spread faster to nearby lymph nodes and other parts of the body even if they are small and in early stages, and they are also more likely to recur.
Cancers are a group of diseases in which some types of cells turn abnormal and multiply without control. Breast cancer is one of the most common cancers that affect women and is the second leading cause of cancer deaths in women. Men can also develop breast cancer, however, breast cancers in men are less than 1% of all breast cancers.
What is HER2-positive breast cancer?
HER2-positive breast cancer means that the breast cancer cells have a higher than normal amount of HER2 proteins on them. HER2 protein is encoded by the HER2 gene, and mutations or too many copies of HER2 genes make breast cells produce too many HER2 proteins, which fuel cancer cell growth.
Human epidermal growth factor receptor-2 (HER2) is a protein that is normally present in all breast cells and regulates cell growth and division. Excessive HER2 protein in cancer cells makes them grow and divide at an abnormally high rate, resulting in HER2-positive breast cancer.
What are the symptoms of HER2 breast cancer?
The most common symptom of most breast cancers, including HER2 breast cancer is a lump in the breast. A painless, hard mass with irregular edges is most likely cancer, but breast cancers can also have a lump that is soft and tender to the touch. Other possible symptoms in the first three stages of breast cancer include:
- Change in the size and shape of the breast
- Swelling of the breast
- Asymmetry in the breast compared to the other
- Skin dimpling or other abnormal changes in the breast’s skin
- Nipple inversion or other nipple abnormalities such as ulceration
- Nipple discharge, especially if bloodstained
- Swollen lymph nodes under the arm or near the collarbone
Symptoms of metastatic cancer depends on where the cancer has spread and can include:
What are the stages of HER2 breast cancer?
All breast cancers are staged by the size of the tumor and extent of spread. Breast cancers are also graded from one to three, based on how abnormal the cancer cells look and how fast they grow. Grade one is low grade cancer and three is high grade which grows and spreads rapidly.
The four stages of breast cancer are:
- Stage I: The tumor is relatively small and localized to the original site with possible spread to the sentinel lymph node, which is the first node the cancer is likely to spread to.
- Stage II: The tumor has grown and spread to a few nearby lymph nodes.
- Stage III: The tumor has grown into many lymph nodes and other breast tissue.
- Stage IV: The cancer has spread (metastatic cancer) to distant parts of the body.
Another classification system is the TMN breast cancer classification, based on Tumor size (T), lymph Node status (N) and distant Metastasis (M). It has many detailed classifications for breast cancers.
What percentage of breast cancers are HER2-positive?
How is HER2 cancer diagnosed?
Samples of breast tissue are removed during a biopsy or surgery and tested in the laboratory to look for presence of HER2 proteins. Commonly used tests to diagnose HER2 positivity include:
- Immunohistochemistry (IHC) test: IHC test uses a chemical dye that stains HER2 protein and reveals its presence. The HER2 protein levels are scored from zero to three. Zero and one are considered HER2-negative, two is inconclusive and three is positive.
- Fluorescence in situ hybridization (FISH) test: FISH test uses fluorescent pieces of DNA that attach to the HER2 gene and show if there are extra copies. FISH tests are usually performed if the IHC result is inconclusive, because they are more expensive and results take longer.
- Inform Dual ISH test: Inform Dual ISH test uses a stain that makes the HER2 protein change color.
The IHC tests are also used to find if the cancer cells have estrogen receptors (ER) and/or progesterone receptors (PR). A positive result indicates that the cancer grows in response to these two female hormones.
Breast cancers are categorized into the following groups based on the HER2 and hormone receptor (HR) status:
- Luminal A: ER- and PR-positive, and HER2-negative breast cancer
- Luminal B: ER-positive, PR-negative and HER2-positive breast cancer
- HER2-positive: HR-negative and HER2-positive breast cancer
- Triple positive: ER-, PR- and HER2-positive breast cancer
- Triple negative (basal like): HR- and HER2-negative breast cancer
Is HER2 breast cancer curable?
The chances of successfully treating HER2 breast cancer is high if the cancer is detected in early stages. HER2 cancers, however, are often high grade tumors in stage III at the time of diagnosis. If HER2 cancer has metastasized at the time of diagnosis, it is treatable but not curable in most individuals.
With the development of medications that specifically target HER2 proteins, HER2-positive breast cancers now have a much better outlook than in the past. HER2-positive cancers that have been in remission for five years are less likely to recur.
- Climate Change May Bring More Fungal Lung Infections
- Healthy Plant-Based Diets Lower Men's Odds for Colon Cancer
- Drinking Rates Crept Up in U.S. States Once Weed Was Made Legal
- Relax, a Little Stress Might Be Good for You
- High Deductibles Keep Some Women From Follow-Up After Troubling Mammogram
- More Health News »
What is the treatment for HER2-positive breast cancer?
Treatment for breast cancers is individualized depending on the type, grade, stage, HR and HER2 status, and any gene mutations. Treatment also depends on the age, overall health and whether the woman is menopausal or not. Treatment may be more complicated if the woman is pregnant. Patients also have the option of enrolling for clinical trials for new treatments.
The primary treatment for all types of breast cancers, including HER2 cancers typically include a combination of two or more of the following:
Most women have surgery as part of the treatment, and surgical procedures may include:
- Lumpectomy: Removal of the tumor with a healthy margin, in low grade early stage cancers.
- Mastectomy: Removal of a whole breast if the cancer has spread to other breast tissue.
- Lymphadenectomy: Removal of sentinel lymph nodes and/or the lymph nodes under the arm, to be tested for cancer.
Many women also undergo a breast reconstruction surgery after surgery for tumor removal. Surgery may also be useful in some situations in metastatic cancers as palliative care.
Radiotherapy is the use of high-energy rays or particles to destroy the cancer cells. Radiotherapy is typically used after surgical removal of cancer, to make sure any remaining cancer cells are destroyed, or if cancer has spread to other parts.
Chemotherapy is the use of medications that can kill cancer cells. Chemotherapy is typically used after surgery, to lower the risk of recurrence, or sometimes before surgery to shrink large localized tumors.
Gene expression tests which evaluate the risk of recurrence are often performed to assess the possible benefit of chemotherapy and individualize the treatment plan based on the patient’s needs. Chemotherapy is also used to treat metastatic breast cancers.
Hormone therapy is given only if the HER2 breast cancer is also positive for hormone receptors. Hormone therapy involves the use of drugs that block hormone receptors, or drugs/surgical procedures that stop production of estrogen in the body.
Targeted therapy medications for HER2-positive cancers block the activity of HER2 proteins by different means. Targeted therapy is used to treat both early and advanced stages of HER2 cancers. Targeted therapy medications for HER2 cancers include:
- Monoclonal antibodies: Monoclonal antibodies are lab-produced antibodies which specifically attach to HER2 proteins in the cancer cells and stop them from growing. Some commonly used targeted therapy medications are:
- Antibody-drug conjugates: Antibody-drug conjugates are antibodies that target and attach to HER2 proteins, and also carry a chemotherapy drug to kill the HER2-positive cells. Examples include:
- Ado-trastuzumab emtansine (Kadcyla or TDM-1)
- Fam-trastuzumab deruxtecan-nxki (Enhertu)
- Kinase inhibitors: HER2 is a type of protein known as kinase, which transmits signals (to grow in the case of HER2) within the cells. Kinase inhibitors stop signaling. Examples of kinase inhibitors are:
- Lapatinib ditosylate (Tykerb)
- Neratinib maleate (Nerlynx)
- Tucatinib (Tukysa)
What is the survival rate of HER2-positive breast cancer?
Survival rates with HER2-positive cancer depends on the stage at the time of diagnosis and response to treatment. The development of targeted therapy has greatly improved survival rates for HER2-positive breast cancer. In advanced stages, HER2-positive cancers respond better to treatment than HER2-negative cancers.
According to recent National Cancer Institute data, the four-year survival rate for combined stages of cancer, based on HR and HER2 status are:
- HR-positive/HER2-negative: 92.5%
- HR-positive/HER2-positive: 90.3%
- HR-negative/HER2-positive: 82.7%
- HR-negative/HER2-negative: 77%
Each person is unique; the data represents the average % survival rate.
Health Solutions From Our Sponsors
Top Is HER2 Cancer Aggressive? Related Articles
Where Breast Cancer SpreadsWhen breast cancer spreads, or metastasizes, it often goes to these five places: the lymph nodes, bones, liver, lungs, and brain. See how breast cancer metastasis affects the body, possible symptoms, and treatment.
Breast Cancer SlidesLearn about breast cancer causes, symptoms, tests, recovery, and prevention. Discover the types of treatments such as surgery and drug therapies as well as the survival rate for breast cancer.
Breast Cancer QuizThis Breast Cancer Quiz features signs, symptoms, facts, causes, common forms, terms, risk factors, statistics, and more. Increase your awareness of breast cancer now!
What Is the BRCA Gene?BRCA genes (BRCA 1 and 2, when normal, repair damaged DNA) are among the genetic mutations linked to breast cancer, ovarian cancer, and other cancers when mutated. Every woman with a BRCA mutation is at high risk for breast cancer, irrespective of whether she has a family history of breast cancer or not. By age 80, a woman with a BRCA mutation has about an 80% chance of developing breast cancer. BRCA1 and BRCA2 gene mutations also increase the risk of ovarian cancer, by 54% and 23%, respectively.
Breast Cancer Symptoms and SignsIn most cases, there are no early warning signs of breast cancer. Breast cancer may not produce any early symptoms, and in many cases, it is first discovered on screening mammography. The most common sign of breast cancer is a new lump or mass in the breast.
HER2-Positive Breast CancerIn about 10%-20% of breast cancers, the cancer cells test positive for HER2, sometimes referred to as the HER2/neu protein. HER2 is a growth-promoting protein located on the surface of some cancer cells. HER2-positive breast cancers tend to grow more rapidly and spread more aggressively than breast cancers that are HER2-negative. Doctors do not know what specifically causes some breast cancers to express this protein while others do not.
Breast Cancer StagesBreast cancer staging is the determination of the extent and spread of the cancer. An individual's health care team uses stages to summarize the extent of the cancer in a standardized way that is recognized by all health care providers. They use this staging to determine the treatment most appropriate for the type of cancer. Cancer staging helps to determine the prognosis, or outlook, of a cancer, including rates of recurrence and survival rates.
Breast Cancer TreatmentBreast cancer treatments depend upon the type of breast cancer that is present as well as the stage (extent of spread) of the tumor. Treatment for early breast cancer typically involves surgery to remove the tumor. After surgery, medical professionals may administer radiation therapy, chemotherapy, or targeted therapy.
Can HER2-Positive Breast Cancer Be Cured?HER2-positive breast cancer is associated with cancer cells that have extra copies of the HER2 gene and produce extra HER2 receptor proteins. With recent advances in medicine, it is considered that HER2-positive breast cancer is curable.
Chemotherapy Treatment for Breast CancerChemotherapy refers to medications that are administered to kill or slow the growth of cancerous cells. Chemotherapy may be given orally or intravenously. Side effects of breast cancer chemotherapy may include nausea, vomiting, hair loss, increased risk of infection, fatigue, and easy bruising. Receiving chemotherapy causes changes in a woman's menstrual cycle.
Is Chemo Necessary for HER2 Positive?The HER2 protein is a kind of receptor found on the surface of breast cells. Chemotherapy is typically used to shrink a tumor before it is removed from the breast with surgery.
Radiation Therapy for Breast CancerRadiation refers to high-energy rays that are directed at the breast to kill or slow the growth of cancer cells. Radiation reduces the risk of local cancer recurrence in the breast. Potential side effects include skin redness, swelling, peeling, and fatigue. It is necessary to undergo follow-up exams and diagnostic X-rays after completing radiation therapy for breast cancer.