Estrogen receptor (ER)

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`BIO-ESTROGEN-RECEPTOR`
Type	Biomarker
Aliases	Estrogen receptorЕстрогеновий рецептор (ЕР)
Status	pending_clinical_signoff
Diseases	None declared
Sources	None declared

Biomarker Facts

Biomarker type	protein_expression_ihc
Measurement	MethodImmunohistochemistry on FFPE tumor tissue (ASCO/CAP-validated antibody) Unitspercent of tumor nuclei staining Typical range 0 100
Related biomarkers	`BIO-PROGESTERONE-RECEPTOR` `BIO-HER2-SOLID`

Notes

Foundational biomarker for breast cancer subtype assignment. Drives endocrine therapy eligibility and CDK4/6i indication. Cross-validated with PR for HR-positive classification.

Used By

Biomarker

BIO-ESR1 - ESR1 mutation (ligand-binding domain)
BIO-HER2-LOW - HER2-low (breast — IHC 1+ OR IHC 2+ ISH-negative)
BIO-HER2-ULTRALOW - HER2-ultralow (breast — IHC > 0 < 1+; faint/incomplete membrane staining ≤10%)
BIO-PIK3CA-H1047R - PIK3CA H1047R mutation
BIO-PROGESTERONE-RECEPTOR - Progesterone receptor (PR)

Indications

IND-BREAST-BRCA-MET-TALAZOPARIB - IND-BREAST-BRCA-MET-TALAZOPARIB
IND-BREAST-HER2-LOW-2L-DATO-DXD - IND-BREAST-HER2-LOW-2L-DATO-DXD
IND-BREAST-HR-POS-1L-INAVOLISIB - IND-BREAST-HR-POS-1L-INAVOLISIB
IND-BREAST-HR-POS-2L-AKT-CAPIVASERTIB - IND-BREAST-HR-POS-2L-AKT-CAPIVASERTIB
IND-BREAST-HR-POS-2L-DATO-DXD - IND-BREAST-HR-POS-2L-DATO-DXD
IND-BREAST-HR-POS-2L-ESR1-ELACESTRANT - IND-BREAST-HR-POS-2L-ESR1-ELACESTRANT
IND-BREAST-HR-POS-2L-FUL-EVEROLIMUS - IND-BREAST-HR-POS-2L-FUL-EVEROLIMUS
IND-BREAST-HR-POS-2L-PIK3CA-ALPELISIB - IND-BREAST-HR-POS-2L-PIK3CA-ALPELISIB
IND-BREAST-HR-POS-2L-T-DXD-HER2-LOW - IND-BREAST-HR-POS-2L-T-DXD-HER2-LOW
IND-BREAST-HR-POS-3L-POST-CDK46I-POST-AKT - IND-BREAST-HR-POS-3L-POST-CDK46I-POST-AKT
IND-BREAST-HR-POS-EARLY-ADJ-CDK46I - IND-BREAST-HR-POS-EARLY-ADJ-CDK46I
IND-BREAST-HR-POS-EARLY-ADJ-RIBOCICLIB - IND-BREAST-HR-POS-EARLY-ADJ-RIBOCICLIB
IND-BREAST-HR-POS-MAINT-CDK46I - IND-BREAST-HR-POS-MAINT-CDK46I
IND-BREAST-HR-POS-MET-1L-CDKI - IND-BREAST-HR-POS-MET-1L-CDKI
IND-BREAST-TNBC-2L-BRCA-OLAPARIB - IND-BREAST-TNBC-2L-BRCA-OLAPARIB
IND-BREAST-TNBC-2L-BRCA-TALAZOPARIB - IND-BREAST-TNBC-2L-BRCA-TALAZOPARIB
IND-BREAST-TNBC-2L-DATO-DXD - IND-BREAST-TNBC-2L-DATO-DXD
IND-BREAST-TNBC-2L-SACITUZUMAB - IND-BREAST-TNBC-2L-SACITUZUMAB
IND-BREAST-TNBC-2L-T-DXD-HER2-LOW - IND-BREAST-TNBC-2L-T-DXD-HER2-LOW
IND-BREAST-TNBC-3L-POST-SACI-POST-T-DXD - IND-BREAST-TNBC-3L-POST-SACI-POST-T-DXD
IND-BREAST-TNBC-EARLY-NEOADJUVANT - IND-BREAST-TNBC-EARLY-NEOADJUVANT

Questionnaires

QUEST-BREAST-1L-STUB - Invasive breast cancer — first line

Red flag

RF-BREAST-TNBC - Triple-negative breast cancer (TNBC): estrogen receptor (ER) <1% nuclear staining on IHC...

Tests

TEST-ER-PR-IHC - ER + PR immunohistochemistry on tumor