A hormone-receptor-positive (HR+) tumor is a tumor which consists of cells that express receptors for certain hormones. The term most commonly refers to
estrogen receptor
Estrogen receptors (ERs) are proteins found in cell (biology), cells that function as receptor (biochemistry), receptors for the hormone estrogen (17β-estradiol). There are two main classes of ERs. The first includes the intracellular estrogen ...
positive tumors (i.e. tumors that contain estrogen receptor positive cells), but can also include
progesterone receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone.
In humans, PR is encoded by a single ''PGR'' gene resi ...
positive tumors. Estrogen-receptor-positive tumors depend on the presence of estrogen for ongoing proliferation.
Classification
ER-positive is one of the
Receptor
Receptor may refer to:
* Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse
*Receptor (biochemistry), in biochemistry, a protein molecule that receives and respond ...
statuses identified in the
classification of breast cancer. Receptor status was traditionally considered by reviewing each individual receptor (
ER,
PR,
her2
Receptor tyrosine-protein kinase erbB-2 is a protein that normally resides in the membranes of cells and is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The ...
) in turn, but newer approaches look at these together, along with the
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
grade
Grade most commonly refers to:
* Grading in education, a measurement of a student's performance by educational assessment (e.g. A, pass, etc.)
* A designation for students, classes and curricula indicating the number of the year a student has reach ...
, to categorize
breast cancer
Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...
into several conceptual molecular classes
that have different
prognoses and may have different responses to specific therapies.
DNA microarrays
A DNA microarray (also commonly known as a DNA chip or biochip) is a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to ...
have assisted this approach.
Breast tumors that do not express ER, PR or Her2 are referred to as
triple-negative breast cancer
Triple-negative breast cancer (TNBC) is any breast cancer that either lacks or shows low levels of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) overexpression and/or gene amplification (i.e ...
s.
Treatment
Endocrine treatment may be beneficial for patients with hormone receptor positive breast tumors.
There are two ways for treating these kind of tumors:
* Lowering systemic levels of estrogen, achieved by the use of drugs from the
aromatase inhibitor
Aromatase inhibitors (AIs) are a class of drugs used in the treatment of breast cancer in postmenopausal women and in men, and gynecomastia in men. They may also be used off-label to reduce estrogen conversion when supplementing testosterone exo ...
category. These drugs target one of the enzymes that takes part in the biosynthesis of estrogen.
* Blockage of the estrogen receptors on the cancerous cells, thus preventing estrogen binding, leading to decreased proliferation. Drugs in this category are referred to as SERMs (
selective estrogen receptor modulator
Selective estrogen receptor modulators (SERMs), also known as estrogen receptor agonists/antagonists (ERAAs), are a class of drugs that act on estrogen receptors (ERs). Compared to pure ER agonists–antagonists (e.g., full agonists and silent ...
) since they are able to block estrogen receptors in a selective manner.
See also
*
Tamoxifen
Tamoxifen, sold under the brand name Nolvadex among others, is a selective estrogen receptor modulator used to prevent breast cancer in women and men. It is also being studied for other types of cancer. It has been used for Albright syndrome ...
*
Raloxifene
Raloxifene, sold under the brand name Evista among others, is a medication used to prevent and treat osteoporosis in postmenopausal women and those on glucocorticoids. For osteoporosis it is less preferred than bisphosphonates. It is also used ...
References
Further reading
http://www.breastcancer.org/treatment/hormonal/what_is_it/hormone_role.jsp
{{DEFAULTSORT:Hormone Receptor Positive Tumor
Breast neoplasia