title: Histological Features and Tissue Microarray Taxonomy of Nigerian Breast Cancer Reveal Predominance of the High-Grade Triple-Negative Phenotype.
abstract: BACKGROUND
  Little is known about the biology, molecular profile and hence optimal treatment of African Nigerian breast cancer. The aim of this work, therefore, was to characterize the histology and molecular profile of Nigerian breast cancer.
  
  
  METHODS
  Breast carcinomas from women at 6 centres of similar tribal origin in Nigeria were reviewed and assembled into tissue microarrays (TMAs), and sections were stained for hormone receptors, i.e. estrogen receptor (ER)α, ERβ1, ERβ progesterone receptor (PR) and androgen receptor, cyclin D, HER2, Ki67 and cytokeratins (CKs), i.e. CK5/6 and CK14 (basal) and CK18 and 19 (luminal).
  
  
  RESULTS
  A total of 835 tumours were analysed. The mean age at diagnosis was 48.62 ± 12.41 years. The most common histological subtype was ductal NST (no-special-type) carcinoma (87.3%). Over 90% of the tumours were grade 2 or 3. The predominant molecular phenotype was the non-basal, triple-negative type (47.65%) followed by the HER2-positive group (19.6%). The percentage of ER-, PR- and HER2-positive tumours was 22.4, 18.9 and 18.8%, respectively.
  
  
  CONCLUSIONS
  Nigerian breast cancer predominantly has a high-grade, triple-negative profile. It occurs at a younger age and bears similarities at the molecular level to pre-menopausal breast cancer in white women, with remarkably lower levels of ERβ expression. The early presentation and histological and molecular phenotype may explain the poor prognosis, and tailoring treatment strategies to target this unique profile are required.
authors.affiliation: School of Medical Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: N A
authors.initials: NA
authors.lastname: Titloye
authors.forename: A
authors.initials: A
authors.lastname: Foster
authors.forename: G O
authors.initials: GO
authors.lastname: Omoniyi-Esan
authors.forename: A O
authors.initials: AO
authors.lastname: Komolafe
authors.forename: A O
authors.initials: AO
authors.lastname: Daramola
authors.forename: O A
authors.initials: OA
authors.lastname: Adeoye
authors.forename: A O
authors.initials: AO
authors.lastname: Adisa
authors.forename: A
authors.initials: A
authors.lastname: Manoharan
authors.forename: D
authors.initials: D
authors.lastname: Pathak
authors.forename: M N
authors.initials: MN
authors.lastname: D'Cruz
authors.forename: Y
authors.initials: Y
authors.lastname: Alizadeh
authors.forename: P D
authors.initials: PD
authors.lastname: Lewis
authors.forename: A M
authors.initials: AM
authors.lastname: Shaaban
mesh_terms: D000328:Adult; D000367:Age Factors; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000208:ethnology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008875:Middle Aged; D009549:Nigeria; D010641:Phenotype; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000235:genetics; D011944:Receptors, Androgen / Q000032:analysis / Q000235:genetics; D011960:Receptors, Estrogen / Q000032:analysis / Q000235:genetics; D011980:Receptors, Progesterone / Q000235:genetics; D046888:Tissue Array Analysis; D064726:Triple Negative Breast Neoplasms / Q000175:diagnosis / Q000208:ethnology* / Q000235:genetics / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D007633:Keratins; D018719:Erb-b2 Receptor Tyrosine Kinases; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C410798:AR protein, human