Turkish Journal of Pathology

Türk Patoloji Dergisi

Turkish Journal of Pathology

Turkish Journal of Pathology

2012, Vol 28, Num, 3     (Pages: 238-244)

Immunohistochemical Characteristics of Triple Negative/Basal-like Breast Cancer

Emel Ebru PALA 1, Ümit BAYOL 1, Süheyla CUMURCU 1, Elif KESKİN 1

1 İzmir Tepecik Eğitim Araştırma Hastanesi, Patoloji Bölümü, İzmİr, TÜRKİYE

Department of Pathology, İzmir Tepecik Education and Research Hospital, İZMİR, TURKEY

DOI: 10.5146/tjpath.2012.01130
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Objective: Triple-negative-breast-cancer that accounts for 10-20% of all breast carcinomas is defined by the lack of estrogen receptor, progesterone receptor, HER2 expression, and agressive clinical behavior. Triple-negative-breast-cancer is categorized into basal like and other types. The basal-like subtype is characterized by the expression of myoepithelial/basal markers.

Material and Method: We studied 41 immunohistochemically triplenegative- breast-cancer patients to determine EGFR, Cytokeratine 5/6, p53, Ki67, GCDFP-15 expression profiles, HER2 and Chromosome 17 centromere gene status by fluorescence-in-situ-hybridization method.

Results: Histological type was invasive ductal carcinoma in 90.2% of the tumors. p53, Ki67, GCDFP-15 mean positivity rates were 55.6%, 51.7%, and 3.2%, respectively. GCDFP-15 positivity was noted in 8 cases of which 6 were Cytokeratine 5/6 negative. The cut-off value for Cytokeratine 5/6 positivity was 5%. EGFR immunoreactivity was grouped into 0, 1+ as negative; 2+, 3+ as positive categories. Cytokeratine 5/6 was positive in 56,1%, EGFR was positive in 51.2% of the patients. The relation between Cytokeratine 5/6 and EGFR expression was statistically significant (p<0.01). None of the cases showed HER2 amplification by fluorescence-in-situ-hybridization method.

Conclusion: GCDFP-15 alone is not a useful marker to detect the metastasis of basaloid type breast cancers. Cytokeratine 5/6 and EGFR expressions showed correlation so these markers are reliable to diagnose basaloid type tumors with a 5% cut-off value.

Keywords : Breast, Carcinoma, Immunohistochemistry