title: Androgen receptor-positive triple negative breast cancer: a unique breast cancer subtype.
abstract: BACKGROUND
  The significance of androgen receptor (AR) expression in triple-negative breast cancer (TNBC) is unclear, and published studies so far have been inconclusive.
  
  
  METHODS
  A tissue microarray was constructed using tissue obtained from 119 patients with primary TNBC and stained for AR expression. Other tissue types obtained included recurrent TNBC, normal breast tissue, adjacent ductal carcinoma-in situ (DCIS), lymph node (LN) and distant metastases. Positive AR expression was defined as ≥10% nuclear staining.
  
  
  RESULTS
  Epithelial tissue was present and evaluable in 94 TNBC patients with a total of 177 tissue cores. AR expression in TNBC was 22 of 94 (23%). AR expression was higher in normal breast tissue (88%) and adjacent DCIS (73% overall). All LN metastases from AR-positive TNBC patients were also AR positive; in addition, no AR-negative TNBC patient had AR-positive LNs. AR expression was associated with older patient age (63 vs. 57 years, respectively, p = 0.051) and LN metastases (p = 0.033). Locoregional recurrence and overall/disease-specific survival were similar between AR-positive and AR-negative patients, although AR-positive patients had more advanced disease. On multivariate analysis, the presence of LN metastases was associated with poorer recurrence-free survival in AR-positive patients (hazard ratio, 4.34) (p = 0.031).
  
  
  CONCLUSIONS
  The AR is expressed in normal breast tissue, and expression decreases with advancement to DCIS and invasive cancer. AR-positive TNBC was more common in older patients and had a higher propensity for LN metastases. AR-positive TNBC may represent a breast cancer subtype with unique features that may be amenable to treatment with alternative targeted therapies.
authors.affiliation: Section of Surgical Oncology, Division of General Surgery, Mayo Clinic, Phoenix, AZ, USA.
authors.forename: Lee J
authors.initials: LJ
authors.lastname: McGhan
authors.forename: Ann E
authors.initials: AE
authors.lastname: McCullough
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Protheroe
authors.forename: Amylou C
authors.initials: AC
authors.lastname: Dueck
authors.forename: James J
authors.initials: JJ
authors.lastname: Lee
authors.forename: Rafael
authors.initials: R
authors.lastname: Nunez-Nateras
authors.forename: Erik P
authors.initials: EP
authors.lastname: Castle
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gray
authors.forename: Nabil
authors.initials: N
authors.lastname: Wasif
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Goetz
authors.forename: John R
authors.initials: JR
authors.lastname: Hawse
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Henry
authors.forename: Michael T
authors.initials: MT
authors.lastname: Barrett
authors.forename: Heather E
authors.initials: HE
authors.lastname: Cunliffe
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Pockaj
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D001940:Breast / Q000378:metabolism; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000401:mortality / Q000556:secondary; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000378:metabolism* / Q000401:mortality / Q000556:secondary; D018275:Carcinoma, Lobular / Q000378:metabolism* / Q000401:mortality / Q000556:secondary; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D011944:Receptors, Androgen / Q000378:metabolism*; D015996:Survival Rate; D064726:Triple Negative Breast Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology
chemical_list: C410798:AR protein, human; D014408:Biomarkers, Tumor; D011944:Receptors, Androgen