Tags

Type your tag names separated by a space and hit enter

Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma.
Mod Pathol. 2006 Feb; 19(2):264-71.MP

Abstract

Microarray profiling of invasive breast carcinomas has identified five distinct subtypes of tumors (luminal A, luminal B, normal breast-like, HER2 overexpressing, and basal-like) that are associated with different clinical outcomes. The basal-like subtype is associated with poor clinical outcomes and is the subtype observed in BRCA1-related breast cancers. The aim of this study was to characterize the histologic and immunophenotypic properties of breast basal-like carcinomas that were first positively identified using DNA microarray analysis. Detailed histologic review was performed on 56 tumors with known microarray profiles (23 basal-like, 23 luminal, and 12 HER2+). Immunohistochemistry for estrogen receptor (ER), HER2, EGFR, smooth muscle actin (SMA), p63, CD10, cytokeratin 5/6, cytokeratin 8/18, and vimentin was performed on 18 basal-like, 16 luminal, and 12 HER2+ tumors. The basal-like tumors were grade 3 ductal/NOS (21/23) or metaplastic (2/23) carcinomas that frequently showed geographic necrosis (17/23), a pushing border of invasion (14/23), and a stromal lymphocytic response (13/23). Most basal-like tumors showed immunoreactivity for vimentin (17/18), luminal cytokeratin 8/18 (15/18), EGFR (13/18), and cytokeratin 5/6 (11/18), while positivity for the myoepithelial markers SMA (4/18), p63 (4/18) and CD10 (2/18) was infrequent. All basal-like tumors tested were ER- and HER2-. Morphologic features significantly associated with the basal-like subtype included markedly elevated mitotic count (P<0.0001), geographic tumor necrosis (P=0.0003), pushing margin of invasion (P=0.0001), and stromal lymphocytic response (P=0.01). The most consistent immunophenotype seen in the basal-like tumors was negativity for ER and HER2, and positivity for vimentin, EGFR, cytokeratin 8/18, and cytokeratin 5/6. The infrequent expression of myoepithelial markers in basal-like carcinomas does not support a direct myoepithelial cell derivation of these tumors. These findings should further assist in the identification of basal-like carcinomas in clinical specimens, facilitating treatment and epidemiologic studies of this tumor subtype.

Authors+Show Affiliations

Department of Pathology and Lab Medicine, University of North Carolina, Chapel Hill, NC 27599-7525, USA. cal@med.unc.eduNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

16341146

Citation

Livasy, Chad A., et al. "Phenotypic Evaluation of the Basal-like Subtype of Invasive Breast Carcinoma." Modern Pathology : an Official Journal of the United States and Canadian Academy of Pathology, Inc, vol. 19, no. 2, 2006, pp. 264-71.
Livasy CA, Karaca G, Nanda R, et al. Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma. Mod Pathol. 2006;19(2):264-71.
Livasy, C. A., Karaca, G., Nanda, R., Tretiakova, M. S., Olopade, O. I., Moore, D. T., & Perou, C. M. (2006). Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma. Modern Pathology : an Official Journal of the United States and Canadian Academy of Pathology, Inc, 19(2), 264-71.
Livasy CA, et al. Phenotypic Evaluation of the Basal-like Subtype of Invasive Breast Carcinoma. Mod Pathol. 2006;19(2):264-71. PubMed PMID: 16341146.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma. AU - Livasy,Chad A, AU - Karaca,Gamze, AU - Nanda,Rita, AU - Tretiakova,Maria S, AU - Olopade,Olufunmilayo I, AU - Moore,Dominic T, AU - Perou,Charles M, PY - 2005/12/13/pubmed PY - 2006/3/22/medline PY - 2005/12/13/entrez SP - 264 EP - 71 JF - Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc JO - Mod Pathol VL - 19 IS - 2 N2 - Microarray profiling of invasive breast carcinomas has identified five distinct subtypes of tumors (luminal A, luminal B, normal breast-like, HER2 overexpressing, and basal-like) that are associated with different clinical outcomes. The basal-like subtype is associated with poor clinical outcomes and is the subtype observed in BRCA1-related breast cancers. The aim of this study was to characterize the histologic and immunophenotypic properties of breast basal-like carcinomas that were first positively identified using DNA microarray analysis. Detailed histologic review was performed on 56 tumors with known microarray profiles (23 basal-like, 23 luminal, and 12 HER2+). Immunohistochemistry for estrogen receptor (ER), HER2, EGFR, smooth muscle actin (SMA), p63, CD10, cytokeratin 5/6, cytokeratin 8/18, and vimentin was performed on 18 basal-like, 16 luminal, and 12 HER2+ tumors. The basal-like tumors were grade 3 ductal/NOS (21/23) or metaplastic (2/23) carcinomas that frequently showed geographic necrosis (17/23), a pushing border of invasion (14/23), and a stromal lymphocytic response (13/23). Most basal-like tumors showed immunoreactivity for vimentin (17/18), luminal cytokeratin 8/18 (15/18), EGFR (13/18), and cytokeratin 5/6 (11/18), while positivity for the myoepithelial markers SMA (4/18), p63 (4/18) and CD10 (2/18) was infrequent. All basal-like tumors tested were ER- and HER2-. Morphologic features significantly associated with the basal-like subtype included markedly elevated mitotic count (P<0.0001), geographic tumor necrosis (P=0.0003), pushing margin of invasion (P=0.0001), and stromal lymphocytic response (P=0.01). The most consistent immunophenotype seen in the basal-like tumors was negativity for ER and HER2, and positivity for vimentin, EGFR, cytokeratin 8/18, and cytokeratin 5/6. The infrequent expression of myoepithelial markers in basal-like carcinomas does not support a direct myoepithelial cell derivation of these tumors. These findings should further assist in the identification of basal-like carcinomas in clinical specimens, facilitating treatment and epidemiologic studies of this tumor subtype. SN - 0893-3952 UR - https://www.unboundmedicine.com/medline/citation/16341146/Phenotypic_evaluation_of_the_basal_like_subtype_of_invasive_breast_carcinoma_ L2 - https://doi.org/10.1038/modpathol.3800528 DB - PRIME DP - Unbound Medicine ER -