title: Salivary duct carcinomas can be classified into luminal androgen receptor-positive, HER2 and basal-like phenotypes.
abstract: OBJECTIVE
  The aim of this study was to devise a molecular classification for salivary duct carcinomas (SDCs) based on the similarities between SDCs and breast carcinomas and on characteristics of the microarray-based gene expression profiling-defined molecular subtypes of breast cancer.
  
  
  RESULTS
  Forty-two pure salivary duct carcinomas, 35 of which contained an in-situ component as defined by histological review and/or immunohistochemical analysis, were stained with antibodies for oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR) and cytokeratin (CK) 5/6. Based on these markers, tumours were classified into HER2, luminal androgen receptor-positive, basal-like, luminal and indeterminate phenotype. Analysis revealed that 16.7%, 69%, 4.8%, 9.5% and 0% were of HER2, luminal androgen receptor-positive, basal-like, indeterminate and luminal phenotype, respectively. The in-situ and invasive components displayed the same molecular subtype in all but one case.
  
  
  CONCLUSIONS
  Salivary duct carcinomas can be classified into molecular subgroups approximately equivalent to those in the breast. We also report on the existence of a subgroup of bona fide pure salivary duct carcinomas that have a 'basal-like' phenotype. Understanding the phenotypic complexity of SDCs may help to expedite the identification of novel therapeutic targets for these aggressive tumours.
authors.affiliation: Department of Histopathology, Royal Surrey County Hospital, Guildford, SurreyDivision of Clinical Medicine, University of Surrey, Guildford, SurreyDepartment of Histopathology, Royal Devon and Exeter Hospital, Exeter, DevonThe Breakthrough Breast Cancer Research Centre - Institute of Cancer Research, London, UKDepartment of Pathology, Faculty of Medicine, Charles University in Prague, Plzeň, Czech RepublicDepartment of Pathology, Spedali Civili Brescia, Brescia, ItalyDepartment of Histopathology, Imperial College Healthcare Trust, Charing Cross Hospital, LondonDepartment of Oncology, St Lukes Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey, UK.
authors.forename: Silvana
authors.initials: S
authors.lastname: Di Palma
authors.forename: Roderick H W
authors.initials: RH
authors.lastname: Simpson
authors.forename: Caterina
authors.initials: C
authors.lastname: Marchiò
authors.forename: Alena
authors.initials: A
authors.lastname: Skálová
authors.forename: Marco
authors.initials: M
authors.lastname: Ungari
authors.forename: Ann
authors.initials: A
authors.lastname: Sandison
authors.forename: Stephen
authors.initials: S
authors.lastname: Whitaker
authors.forename: Suzanne
authors.initials: S
authors.lastname: Parry
authors.forename: Jorge S
authors.initials: JS
authors.lastname: Reis-Filho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D002277:Carcinoma / Q000145:classification* / Q000235:genetics / Q000473:pathology; D002278:Carcinoma in Situ / Q000145:classification* / Q000235:genetics / Q000473:pathology; D044584:Carcinoma, Ductal / Q000145:classification* / Q000235:genetics / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D011944:Receptors, Androgen / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D018987:Salivary Ducts / Q000473:pathology; D012468:Salivary Gland Neoplasms / Q000145:classification* / Q000235:genetics / Q000473:pathology; D046888:Tissue Array Analysis; D059467:Transcriptome
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011944:Receptors, Androgen; C410798:AR protein, human; C508053:ERBB2 protein, human