%0 Journal Article
%T Histological and Immunohistochemical Evaluation of Cytokeratin 5/6 Expressing Breast Cancer
%A Arnis Abolins
%A Ilze Strumfa
%A Andrejs Vanags
%A Genadijs Trofimovics
%A Janis Gardovskis
%J Acta Chirurgica Latviensis
%D 2011
%I 
%R 10.2478/v10163-012-0005-9
%X Introduction. Breast cancer represents morphologically, molecularly and prognostically heterogeneous group of tumours. In order to characterise the prognosis more exactly, molecular subtyping has been developed. However, the role of basal markers, including cytokeratin 5/6, (CK5/6) in the immunohistochemical typing of breast cancer still causes significant controversy. Aim of the study was to determine the frequency of CK5/6 expression in invasive breast cancers in Latvian patients and to characterize CK5/6 positive tumours by histology and molecular subtypes in order to clarify the diagnostic role of CK5/6 expression in breast cancer. Materials and methods: Consecutive potentially radically operated invasive breast cancer cases were identified by archive search. The gross and microscopic evaluation was performed on breast cancer protocol basis, aiming at complete description of morphological prognostic factors. Expression of oestrogen (ER) and progesterone (PR) receptors, actin, p53, p63, CK5/6 and Ki-67 was performed by immunohistochemistry. HER2 protein over-expression was detected by HercepTestTM. Molecular subtypes (luminal A, luminal B, HER-2 positive or triple negative) were determined for each tumour using ER, PR, HER-2 expression data. Descriptive statistics including calculation of 95% confidence interval (CI) was carried out by CIA software. Results: Positive CK5/6 expression in tumour cells was observed in 23 (15.9%) cases [95% CI = 10.8-22.7]. No statistically significant differences were found between CK 5/6 positive cases and CK 5/6 negative controls regarding the histological type and grade of breast cancer as well as age of cancer diagnostics. CK 5/6 positive cases mostly were of luminal A (47.8%; 95% CI = 29.2-67.0) or triple negative (43.5%; 95% CI = 25.6-63.3) molecular subtype. CK5/6 expression was found in 43.4 % [95% CI = 25.6-63.1] of triple negative breast cancer cases in contrast to the expression rate 10.7% [95% CI = 6.3-17.3] in other molecular subtypes. Conclusions: Frequency of CK5/6 expression is sufficient to carry out the diagnostic examination. CK 5/6 expression is not limited to single molecular type. Luminal A and triple negative breast cancer constitute the largest groups within CK5/6 positive cases. CK5/6 expression is significantly more frequent in triple negative breast cancer than in other molecular types. However, CK5/6 as a complementary marker for triple negative breast cancer is characterised by low sensitivity although high specifity. CK5/6 positive tumours tend to have higher proliferation fraction.
%K breast cancer
%K molecular subtypes
%K cytokeratin 5/6
%U http://versita.metapress.com/content/c262883876u1r26u/?p=84f9a83e333c4c279d67fe527371dcc4&pi=4