title: Immunohistochemically defined subtypes and outcome of apocrine breast cancer.
abstract: BACKGROUND
  Conflicting data are available in the literature on the outcome of invasive apocrine carcinoma (IAC), possibly related to a heterogeneous classification of these tumors.
  
  
  METHODS
  A series of 6899 consecutive patients with invasive ductal carcinoma (IDC) not otherwise specified and 72 patients with immunohistochemically defined IAC who received surgery at the European Institute of Oncology between 1997 and 2005 were included. We then explored patterns of recurrence of IAC according to 2 immunohistochemically defined tumor subtypes: pure apocrine carcinoma (estrogen [ER] and progesterone [PgR] receptor negative, and AR positive) and apocrine-like carcinoma (ER or PgR positive and AR negative).
  
  
  RESULTS
  The diagnosis of pure apocrine carcinoma was correlated with a worse outcome in terms of DFS (hazard ratio [HR] 1.7; 95% confidence interval [CI], 1.01-2.86; P = .0010) if compared with IDC, whereas IDC and apocrine-like breast cancers showed a similar outcome in terms of DFS and overall survival. Patients with pure apocrine carcinoma had an increased risk in contralateral breast cancer (HR, 4.12; 95% CI, 1.22-14; P = .02).
  
  
  CONCLUSIONS
  Pure apocrine carcinoma represents a distinct subtype of breast cancer with a significantly worse DFS as compared with IDC. AR determination might have an important prognostic implication in IAC. Moreover, AR-targeted therapy should be further explored within these tumors.
authors.affiliation: Research Unit in Medical Senology, Department of Medicine, European Institute of Oncology, Milan, Italy. silvia.dellapasqua@ieo.it
authors.forename: Silvia
authors.initials: S
authors.lastname: Dellapasqua
authors.forename: Patrick
authors.initials: P
authors.lastname: Maisonneuve
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Viale
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pruneri
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mazzarol
authors.forename: Raffaella
authors.initials: R
authors.lastname: Ghisini
authors.forename: Manuelita
authors.initials: M
authors.lastname: Mazza
authors.forename: Monica
authors.initials: M
authors.lastname: Iorfida
authors.forename: Nicole
authors.initials: N
authors.lastname: Rotmensz
authors.forename: Paolo
authors.initials: P
authors.lastname: Veronesi
authors.forename: Alberto
authors.initials: A
authors.lastname: Luini
authors.forename: Aron
authors.initials: A
authors.lastname: Goldhirsch
authors.forename: Marco
authors.initials: M
authors.lastname: Colleoni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001050:Apocrine Glands / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000145:classification* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000145:classification* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D018275:Carcinoma, Lobular / Q000145:classification* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011944:Receptors, Androgen / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone