Stains
Androgen receptor (AR)


Topic Completed: 1 February 2018

Revised: 13 May 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Androgen receptor[title] breast cancer "loattrfree full text"[sb]

Gina Johnson, M.D.
Monika Roychowdhury, M.D.
Page views in 2019 to date: 1,409
Cite this page: Johnson G, Roychowdhury M. Androgen receptor (AR). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/stainsAR.html. Accessed September 22nd, 2019.
Definition / general
  • Androgen receptor (AR) is a member of the superfamily of ligand responsive transcription regulators
  • It functions in the nucleus where it is believed to act as a transcriptional regulator mediating the action of androgens
  • 918 amino acid protein encoded by a single copy gene on X q11 - q12
Essential features
  • Expressed variably by both ER / PR+ as well as ER / PR- breast cancers
  • Most useful for triple negative breast cancer, luminal androgen subtype
  • Detected by IHC or gene classifier (molecular testing)
  • Predicts favorable prognosis in early stage disease based on current studies, some controversy exists
  • Ongoing trials to study the effect of androgen receptor targeted therapy in
    • AR+ triple negative breast cancer
    • Hormone receptor positive metastatic breast cancer
    • HER2+ metastatic breast cancer
Pathophysiology
  • Expressed in two types of mammary epithelial cells:
    • Metaplastic apocrine cells (lack ER / PR)
    • Luminal epithelial cells (5 - 30%) (co-expressed with ER / PR)
Diagnosis
  • May be detected by gene classifier or IHC
  • Any nuclear IHC staining in tumor cells is considered as positive result but further subdivided into subgroups with 1 - 10% and > 10% positive staining
Clinical features
Uses by pathologists
  • Apocrine marker
  • Breast carcinoma marker helpful in determining primary site of metastases
  • Paget disease marker
  • Sebaceous carcinoma marker; may help differentiate from squamous cell and basal cell carcinomas (Am J Clin Pathol 2010;134:22)
Treatment
Microscopic (histologic) description
  • Nuclear stain in tumor cells is quantified
Microscopic (histologic) images

Contributed by Monika Roychowdhury, M.D.

Skin metastatic breast carcinoma 20x

Androgen receptor
in metastatic breast
carcinoma 20x

Skin metastatic breast carcinoma 40x

Androgen receptor
in metastatic breast
carcinoma 40x


Case of the Week #214

Salivary gland AR-
low grade cribriform
cystadenocarcinoma



Images hosted on other servers:

Breast: apocrine DCIS

Breast: apocrine metaplasia

Prostate carcinoma
metastatic to bone

Spindle cell lipoma

Positive staining - normal
Positive staining - disease
Negative staining
Board review question #1
Androgen receptor testing is most useful in:

  1. ER+, PR+, HER2+ breast tumor
  2. ER+, PR+, HER2- breast tumor
  3. ER-, PR-, HER2+ breast tumor
  4. ER-, PR-, HER2- breast tumor
Board review answer #1
D. ER-, PR-, HER2- breast tumor

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