HR stands for hormone receptor, and HER2 stands for human epidermal growth factor receptor 2. Learn about the difference between these types of breast cancer.
What is HR in breast cancer?
Breast cells express certain proteins on their surface called hormone receptors (HRs) that act as binding sites to the hormones estrogen or progesterone. This binding or reception of signals from the hormone results in the increased growth of breast cells.
Breast cancer occurs when there is an uncontrolled growth of cells in the breast. Due to certain abnormalities, certain breast cancer cells may not respond to the various regulators of cell growth and division and thus may not carry HRs for estrogen (ER), progesterone (PR), or both:
- HR− breast cancer occurs when the cancer cells carry none of the HRs
- HR+ breast cancer occurs when the cancer cells carry either or both of the HRs
Almost 66% of breast cancer cases are HR+. Of the HR+ cases, about 80% are either ER+ or both ER/PR+.
What is HER2 in breast cancer?
Another receptor protein that is present on the breast cell surface is called the human epidermal growth factor receptor 2 (HER2) receptor. It is sometimes called the HER2/neu receptor and helps in the growth, division, and repair of breast cells.
Some breast cancer cells may have a genetic mutation called HER2 gene amplification, which may cause the overexpression of HER2 receptors. This makes cancer cells multiply rapidly.
Breast cancer cells with HER2 protein overexpression are called HER2+ breast cancer. About 10%-20% of breast cancer are HER2+.
What is triple negative breast cancer?
Triple negative breast cancer (TNBC) means that the cancer cells do not have estrogen (ER) and progesterone (PR) on their surface, and they do not over-express the HER2 protein as well (HER2−). In contrast to TNBC, triple positive breast cancer means the cancer cells are ER+, PR+, and HER2+.
TNBC accounts for about 10%-15% of breast cancer cases. Patients with TNBC tend to have a worse outcome compared to those with other types of breast cancer due to the following factors:
- TNBC tends to grow more rapidly and aggressively
- There are fewer treatment options for TNBC
Factors that may increase the risk of this type of breast cancer include:
- Age (women younger than 40 are more likely to have TNBC than older women)
- African American ethnicity
- BRCA1 mutation (BRCA1 is a type of gene associated with certain types of cancer such as breast, ovarian, prostate, and pancreatic cancer)
Why is HR status important in breast cancer?
Knowing the hormone receptor (HR) status is important in planning breast cancer treatment and predicting prognosis.
If breast cancer is HR+, medications can be given to block particular HRs on breast cancer cells. Blocking the receptor means that the cancer cells will not grow and multiply in response to the hormones and will eventually die or slow their growth.
Additionally, medications may be administered to lower estrogen levels, which will help limit the growth of HR+ cancer cells. If, however, the cancer cells are negative for both estrogen (ER) and progesterone (PR), these hormone drugs will not be effective. Furthermore, if the cancer cells are HER2−, medications that target HER2 receptors cannot be used.
HR+ breast cancer tends to have a better prognosis than HR− breast cancer.
How do doctors diagnose HR or HER2 breast cancer?
Doctors can confirm whether you have HR+ or HR− cancer through an immunohistochemistry test. For this test, a biopsy is done to collect a sample of tumor tissue and send it to a lab for examination.
A similar test can be done to determine whether breast cancer is HER2+ or HER2−. A part of the HER2 protein may be shed from the surface of breast cancer cells. This can be detected in a serum using a method called enzyme-linked immunosorbent assay.
|Luminal A||Estrogen (ER) and progesterone (PR) positive and HER2− breast cancer|
|Luminal B||ER+, PR−, and HER2+ breast cancer|
|HER2+||HR− and HER2+ breast cancer|
|Triple positive||ER, PR, and HER2+ breast cancer|
|Triple negative||HR and HER2− breast cancer|
- What Is Avascular Necrosis and How Does It Affect Bones?
- The Arch of the Human Foot Was Key to Upright Walking, Scientists Say
- Worried About Cataracts? Here's What You Need to Know
- FDA Issues Warning About Compounded Versions of Wegovy, Ozempic
- Sick Restaurant Workers Fuel Many Foodborne Illness Outbreaks
- More Health News »
Health Solutions From Our Sponsors
Top What Is HR and HER2 Breast Cancer Related Articles
anastrozoleAnastrozole is a medication used in the treatment of certain types of breast cancer in postmenopausal women. Anastrozole is used in different stages of breast cancer to prevent, halt or slow down the progression of cancer growth. Common side effects of anastrozole include hot flashes, dilation of blood vessels, high blood pressure (hypertension), cardiovascular disease, heart attack (myocardial infarction), ischemic cerebrovascular event, blood clot block in vein (venous thromboembolic event), deep venous thromboembolic event, inflammation with clot in the vein (thrombophlebitis), chest pain related to coronary artery disease (angina pectoris), nausea, vomiting, diarrhea, constipation, indigestion (dyspepsia), gastrointestinal disorder, loss of appetite (anorexia), dry mouth (xerostomia), joint inflammation (arthritis), and others. Do not take if pregnant, you may become pregnant, or are breastfeeding.
Breast cancer is an invasive tumor that develops in the mammary gland. Breast cancer is detected via mammograms, breast self-examination (BSE), biopsy, and specialized testing on breast cancer tissue. Treatment of breast cancer may involve surgery, radiation, hormone therapy, chemotherapy, and targeted therapy. Breast cancer risk may be lowered by managing controllable risk factors.
What you should know about breast cancer
- Breast cancer is the most common cancer among American women.
- One in every eight women in the United States develops breast cancer.
- There are many types of breast cancer that differ in their capability of spreading (metastasize) to other body tissues.
- The causes of breast cancer are unknown, although medical professionals have identified a number of risk factors.
- There are 11 common types of breast cancer and 4 uncommon types of breast cancer.
- Breast cancer early signs and symptoms include
- a lump in the breast or armpit,
- bloody nipple discharge,
- inverted nipple,
- orange-peel texture or dimpling of the breast's skin (peau d'orange),
- breast pain or sore nipple,
- swollen lymph nodes in the neck or armpit, and
- a change in the size or shape of the breast or nipple.
- Breast cancer can also be symptom free, which makes following national screening recommendations an important practice.
- Breast cancer is diagnosed during a physical exam, by a self-exam of the breasts, mammography, ultrasound testing, and biopsy.
- Treatment of breast cancer depends on the type of cancer and its stage (0-IV) and may involve surgery, radiation, or chemotherapy.
Young Women & Breast CancerIs breast cancer genetic? Should I get tested for the BRCA gene? What every young women should know about breast cancer. Discover the signs and symptoms of breast cancer and other crucial breast cancer facts.
Breast Cancer Follow-Up Self-ExamA breast cancer follow-up self-exam is a test that may help a woman detect a recurrence of the disease. A woman should perform a monthly self-exam of both breasts as well as attend scheduled follow-up appointments to detect any breast cancer recurrence early. Lymph node involvement, tumor size, hormone receptor status, histologic grade, nuclear grade, and oncogene expression help determine the likelihood of a recurrence.
Breast Cancer in ChildrenBreast cancer is the most commonly occurring cancer globally. It is mostly seen in women, whereas men are rarely affected. Breast tumors are occasionally seen in children and are mostly benign (noncancerous) and thought to be harmless. Breast lumps in children are known as fibroadenomas, and girls are more likely to develop these tumors. There is no standard staging of breast cancer in children.
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.
What Questions Should I Ask My Doctor About Breast Cancer?A diagnosis of breast cancer can be overwhelming, so it's important to write down all your questions before meeting with your doctor.
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!
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.
exemestaneExemestane is a medication approved for the treatment of advanced breast cancer in postmenopausal women, and is also used off-label to prevent breast cancer in high-risk premenopausal women. Common side effects of exemestane include fatigue, hot flashes, pain, headache, insomnia, depression, joint pain (arthralgia), low count of lymphocyte white blood cells (lymphocytopenia), nausea, high blood pressure (hypertension), chest pain, and others. Do not take if pregnant or breastfeeding.
fluorouracilFluorouracil (5-FU) injection is a chemotherapy medication used in the treatment of some cancers including gastric, pancreatic, colorectal, and breast cancers in adults. Common side effects of fluorouracil include nausea, vomiting, diarrhea, loss of appetite (anorexia), oral inflammation (stomatitis), inflammation of the throat and esophagus (esophagopharyngitis), reduced blood flow to the intestinal region (mesenteric ischemia), gastrointestinal (GI) tissue sloughing, GI ulcer, GI hemorrhage, plaque buildup in coronary arteries (coronary arteriosclerosis), chest pain associated with coronary artery disease (angina pectoris), irregular heart rhythm (cardiac arrhythmia), and others.
Genetic Testing for Breast CancerIntensive genetic counseling is required before undergoing genetic tests for breast cancer. During this educational counseling session, the health care provider can fully explain the benefits and risks of genetic testing and answer any questions you may have. You will also be required to sign a consent form prior to participating in any genetic tests. The form is an agreement between you and your doctor, showing that you have discussed the test and how its results might affect your family.
megestrolMegestrol is a synthetic form of progesterone, one of the female sex hormones, and has effects similar to the natural hormone. Megestrol is used to treat extreme weight loss and muscle wasting syndrome (cachexia) associated with acquired immunodeficiency syndrome (AIDS), the advanced stage of human immunodeficiency virus (HIV) infection, and advanced breast and endometrial cancers. Common side effects of megestrol include diarrhea, gas (flatulence), nausea, vomiting, indigestion (dyspepsia), abdominal pain, constipation, oral Candida yeast infection (moniliasis), dry mouth (xerostomia), excessive salivation (sialorrhea), skin rash, hair loss (alopecia), and others. Do not take if pregnant or breastfeeding.
paclitaxelPaclitaxel is a chemotherapy drug used to treat various types of cancers including ovarian cancer, breast cancer, non-small cell lung cancer, and AIDS-related Kaposi sarcoma. Common side effects of paclitaxel include blood disorders, bleeding, infections, injection site reaction, leakage of drug out of the vein (extravasation), skin rash, hair loss (alopecia), hypersensitivity reactions, severe allergic reaction (anaphylaxis), severe skin reactions, nausea, vomiting, diarrhea, sore mouth (stomatitis), and others. Do not use if pregnant or breastfeeding.
palbociclibPalbociclib is a chemotherapy drug used to treat HER2-negative and HR-positive breast cancers in women and men, which are advanced or have spread to other organs (metastatic), in combination with an anti-estrogenic drug. Palbociclib can cause fetal harm as well as male infertility. Common side effects of palbociclib/letrozole or fulvestrant combination therapy include blood disorders, infections, fatigue, weakness (asthenia), high temperature (pyrexia), nausea, vomiting, diarrhea, oral inflammation (stomatitis), decreased appetite, increase in liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST), taste disorder (dysgeusia), hair loss (alopecia), and others. Do not take if breastfeeding.
Radiation Therapy for Breast CancerRadiation therapy for breast cancer is a form of treatment that utilizes high-energy rays to kill cancer cells. Check out the center below for more medical references on breast cancer, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.
Breast Cancer Treatment by Stage
Treatment of breast cancer depends upon the stage of the cancer at the time of diagnosis. Some of the various treatments include:
- hormone therapy,
- radiation therapy,
- HER2-targeted therapy,
- neoadjuvant therapy, and
- adjuvant therapy.
What Are the Four Types of Breast Cancer?The four most common types of breast cancer are ductal carcinoma in situ, lobular carcinoma in situ, invasive ductal carcinoma, invasive lobular carcinoma. The designations are based on the locations of the tumors, whether they have spread and where they have spread to.