Abstract

Objective. The aim of this study was to highlight p53 expression during metastatic progression of invasive breast carcinoma of no special type (NST) and to evaluate its role in stratifying patients based on molecular classification. Material and Methods. The specimens, primary tumors and corresponding lymph node metastases (LNM) from 84 patients were immunohistochemically stained for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER)-2, basal cytokeratin CK5 and nuclear proteins Ki67, p53. Results. No statistical significant differences of p53 expression were found between the two compared sites, but the p53 instability was found in 11 cases (13.2%). Switch of molecular subtype was noticed in 22.62% of cases. Only 5 cases of p53 transitions, from positive to negative status, were involved in molecular subtypes switch, from Luminal B to Luminal A. Conclusions. The p53 marker and molecular subtypes are not stable during tumor progression. Breast cancer during its metastatic development can gain or lose the p53 expression and cases developed with p53 vanishing in metastasis prevailed. A link between p53 instability and molecular subtypes switch was found only between p53 loss and Luminal B to Luminal A transition.

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