Intermediate
Technical
IVT
estrogen receptor positive
Breast cancer cells that have estrogen receptors and typically respond to hormone-blocking treatments.
Full Definition
Estrogen receptor positive (ER+) breast cancer refers to tumors where at least 1% of cancer cells have estrogen receptors that can bind to the hormone estrogen. These receptors can stimulate cancer cell growth when estrogen is present. ER+ status is determined through immunohistochemistry testing and is crucial for treatment planning, as these cancers typically respond well to hormone therapy such as tamoxifen or aromatase inhibitors. Approximately 70-80% of breast cancers are ER+.
Usage
Usage note: Use ER+ abbreviation only after first mention of full term in document.
In Context
- "The tumor was estrogen receptor positive with 85% nuclear staining intensity." — Pathology report
- "Patients with estrogen receptor positive tumors are candidates for adjuvant endocrine therapy." — Treatment guideline
Also known as
ER+
ER-positive
hormone receptor positive
Contrasted with
estrogen receptor negative
ER-negative
Don't confuse with
progesterone receptor positive
HER2-positive