Breast malignant, males, children
Carcinoma subtypes
Luminal phenotype

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 28 December 2016, last major update August 2012

Copyright: (c) 2001-2016, PathologyOutlines.com, Inc.

PubMed search: luminal [title] phenotype carcinoma breast

Cite this page: Luminal phenotype. PathologyOutlines.com website. http://pathologyoutlines.com/topic/breastmalignantluminal.html. Accessed November 21st, 2017.
Definition / general
  • Defining molecular feature is ER expression
  • Major difference between luminal A and luminal B breast cancers is degree of proliferation and HER2 expression signature, which is more pronounced in luminal B (Breast Care (Basel) 2011;6:258)
Terminology
  • Not part of current WHO breast classification
Clinical features
  • Classification is based on gene expression (molecular) profile studies; subtype reflects clustering of genes activated by ER signaling pathways
  • Distribution by molecular typing is: luminal A: 71%; luminal B: 8%; HER2+: 6% basal-like: 15% (Ann Surg Oncol 2009;16:2705)
  • Luminal subtypes include luminal A (ER+ [strong], PR+, HER2-) and luminal B (ER+ [weak / moderate], PR-, sometimes HER2+)
  • Some authors also include categories of luminal A-HER2 and luminal B-HER2 hybrids (Int J Clin Exp Pathol 2009;2:444)
  • Luminal cytokeratins are CK7 / 8, 18 and 19
  • Luminal A and B subtypes are associated with mutations in E-cadherin and MAP2K4, and amplifications of Cyclin D1, HER2 and HDM2 (Breast Cancer Res Treat 2010;121:53)
  • Luminal A breast cancers are usually low grade, with slow growth and better prognosis than luminal B (J Natl Cancer Inst 2009;101:736)
  • Luminal B breast cancers: some are HER2+, but the major biological distinction from Luminal A is the proliferation signature, in which CCNB1, MKI67 and MYBL2 genes have higher expression in luminal B than in luminal A tumors (BMC Genomics 2006 Apr 27;7:96)
  • Luminal A and most grade 1 luminal B (HER2+) cases are low proliferative (Breast Cancer 2014;21:47)
Microscopic (histologic) images
Images hosted on other servers:

Classic Luminal A tumor is ER+ (strong), Ki67 low

Uncommonly, Luminal A tumor has high Ki67 index

Positive stains