Abstract

INTRODUCTION

Breast cancer is the second most common cancer in women and the second leading cause of cancer death. p53 is an important tumor suppressor that plays a central role in cell cycle and TP53 gene mutations are detected in about 20-30% of patients with breast cancer. The correlation between TP53 gene mutation and immunohistochemical p53 expression has been demonstrated. The present study aims to evaluate the prognostic significance of immunohistochemical p53 expression in breast cancer patients.

METHODS

The present study evaluated patients with breast cancer who were diagnosed at Izmir Katip Celebi University, Ataturk Training and Research Hospital, Department of Pathology from 2006 to 2012, and who were followed up at the Medical Oncology clinic. Immunohistochemical nuclear p53 expression was assessed in relation to pathological and clinical prognostic factors.

RESULTS

This study included 395 patients with breast cancer. p53 expression was detected in 203 (51.4%) patients. The p53 staining values were compared according to molecular subtypes; p53 expression was the lowest in luminal A and Luminal B-Her2 negative groups. The p53 staining percentages in luminal A and luminal B-Her2 negative groups were found to be statistically significantly different when compared to other subtypes (p<0.05). Patients were divided into two groups according to p53 expression and no difference in survivals was found between the two groups. p53 expression was positively correlated with both Ki-67 proliferation index and histological grade, and there was a negative correlation between p53 expression and estrogen receptor expression (p<0.05).

DISCUSSION AND CONCLUSION

In this study, it has been shown that p53 expression may be associated with poor prognosis. The increased preclinical and clinical studies on treatments targeting mutant p53 protein will reveal the prognostic and predictive importance of immunohistochemical p53 expression.