Identification of a basal-like subtype of breast ductal carcinoma in situ

Hum Pathol. 2007 Feb;38(2):197-204. doi: 10.1016/j.humpath.2006.08.017.


Microarray profiling of invasive breast carcinomas has identified subtypes including luminal A, luminal B, HER2-overexpressing, and basal-like. The poor-prognosis, basal-like tumors have been immunohistochemically characterized as estrogen receptor (ER)-negative, HER2/neu-negative, and cytokeratin 5/6-positive and/or epidermal growth factor receptor (EGFR)-positive. The aim of this study was to determine the prevalence of basal-like ductal carcinoma in situ in a population-based series of cases using immunohistochemical surrogates. A total of 245 pure ductal carcinoma in situ cases from a population-based, case-control study were evaluated for histologic characteristics and immunostained for ER, HER2/neu, EGFR, cytokeratin 5/6, p53, and Ki-67. The subtypes were defined as: luminal A (ER+, HER2-), luminal B (ER+, HER2+), HER2 positive (ER-, HER2+), and basal-like (ER-, HER2-, EGFR+, and/or cytokeratin 5/6+). The prevalence of breast cancer subtypes was basal-like (n = 19 [8%]); luminal A, n = 149 (61%); luminal B, n = 23 (9%); and HER2+/ER-, n = 38 (16%). Sixteen tumors (6%) were unclassified (negative for all 4 defining markers). The basal-like subtype was associated with unfavorable prognostic variables including high-grade nuclei (P < .0001), p53 overexpression (P < .0001), and elevated Ki-67 index (P < .0001). These studies demonstrate the presence of a basal-like in situ carcinoma, a potential precursor lesion to invasive basal-like carcinoma.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Breast Neoplasms / classification
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Carcinoma, Intraductal, Noninfiltrating / classification
  • Carcinoma, Intraductal, Noninfiltrating / metabolism
  • Carcinoma, Intraductal, Noninfiltrating / pathology*
  • ErbB Receptors / analysis
  • Female
  • Humans
  • Immunohistochemistry
  • Keratin-5 / analysis
  • Keratin-6 / analysis
  • Ki-67 Antigen / analysis
  • Middle Aged
  • Prognosis
  • Receptor, ErbB-2 / analysis
  • Receptors, Estrogen / analysis
  • Tissue Array Analysis
  • Tumor Suppressor Protein p53 / analysis


  • Keratin-5
  • Keratin-6
  • Ki-67 Antigen
  • Receptors, Estrogen
  • Tumor Suppressor Protein p53
  • ErbB Receptors
  • Receptor, ErbB-2