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 a group of proteins found inside cells. They are receptors that are activated by the hormone estrogen (17β-estradiol). Two classes of ER exist: nuclear estrogen receptors ( ERα and ERβ), which are members of the ...

positive tumors (i.e. tumors that contain estrogen receptor positive cells), but can also include progesterone receptor 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 structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a ...

statuses identified in the

classification of breast cancer Breast cancer classification divides breast cancer into categories according to different schemes criteria and serving a different purpose. The major categories are the histopathological type, the grade of the tumor, the stage of the tumor, and ...

. Receptor status was traditionally considered by reviewing each individual receptor ( ER, PR,

her2 Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently refer ...

) 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: * Grade (education), a measurement of a student's performance * Grade, the number of the year a student has reached in a given educational stage * Grade (slope), the steepness of a slope Grade or grading may also ref ...

, to categorize

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a r ...

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 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 g ...

have assisted this approach.

Diagnosis

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 ex ...

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 also referred to as SERMs ( Selective estrogen receptor modulator) since they are able to block estrogen receptors in a selective manner.

Classification

Diagnosis

Treatment

See also

References

Further reading