Skip to main content

Estrogen Receptor-Positive Breast Cancer

Meaning

Estrogen Receptor-Positive Breast Cancer, often abbreviated as ER+, is a specific subtype of malignancy where the cancer cells possess functional receptors for the hormone estrogen on their surface or within their cytoplasm. The presence of these receptors indicates that the tumor’s growth and proliferation are significantly stimulated by circulating estrogen, making it a key driver of the disease’s progression. This biological characteristic is clinically crucial because it renders the cancer susceptible to endocrine-based therapies that block the estrogen signal. This subtype accounts for the majority of breast cancer diagnoses, emphasizing the profound link between the endocrine system and oncology.