Effect of Ki-67 on Immunohistochemical Classification of Luminal A to Luminal B Subtypes of Breast Carcinoma.

Autor: Cirqueira, Magno Belém, Moreira, Marise Amaral Rebouças, Soares, Leonardo Ribeiro, Cysneiros, Maria‐Auxiliadora de Paula Carneiro, Vilela, Maria‐Helena Tavares, Freitas‐Junior, Ruffo
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Zdroj: Breast Journal; Sep/Oct2015, Vol. 21 Issue 5, p465-472, 8p
Abstrakt: It has recently been proposed to include an immunohistochemical marker of cell proliferation, Ki-67, as an element with which to classify the molecular subtypes of breast cancer. The objective of this study was to evaluate the effect of the introduction of the Ki-67 marker on the molecular classification of breast cancer by immunohistochemistry. This study was performed on 234 cases of invasive ductal carcinoma of the breast submitted to two immunohistochemical classification panels, one including Ki-67 and the other not. The data obtained with the two classifications were correlated with well-established prognostic factors such as histologic grade, the number of lymph nodes affected and tumor size. The molecular classification without Ki-67 identified: 136 cases of luminal A (58.1%), 19 cases of luminal B (8.1%), 27 cases of human epidermal growth-factor receptor 2 overexpressing (11.5%), 27 cases of basal-like (11.5%), and 25 cases of nonbasal-like triple-negative tumors (10.7%). When Ki-67 was included, this situation changed significantly, with the following cases being identified: 72 cases of luminal A (30.8%) and 83 cases of luminal B tumors (35.5%), resulting in a Kappa score of 0.216. Evaluation of correlations between the luminal A and luminal B tumor subtypes and the selected prognostic factors showed a statistically significant difference only when Ki-67 was included and only with respect to histologic grade (p < 0.001). The new classification with Ki-67 significantly altered the prevalence of the luminal A and luminal B subtypes and improved correlation with the histologic grade. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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