Prognostic Significance of Immunohistochemical P53 Expression in Patients with Breast Cancer

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.

Meme Kanseri Tanýlý Hastalarda Ýmmunhistokimyasal Olarak P53 Ekspresyonunun Prognostik Önemi

GÝRÝÞ ve AMAÇ: Meme kanseri kadýnlarda en sýk görülen ve ölüme neden olan kanserler arasýnda ikinci sýrada yer almaktadýr. p53 hücre siklusunda santral rol oynayan önemli bir tümör supresördür ve meme kanserinde yaklaþýk %20-30 oranýnda TP53 gen mutasyonu saptanmaktadýr. TP53 gen mutasyonu ve immunhistokimyasal p53 ekspresyonu korelasyonu gösterilmiþtir. Bu çalýþmada meme kanseri hastalarýnda immunhistokimyasal p53 ekspresyonunun prognostik öneminin deðerlendirilmesi amaçlanmýþtýr.
YÖNTEM ve GEREÇLER: Bu çalýþmaya 2006-2012 yýllarý arasýnda Ýzmir Katip Çelebi Üniversitesi Atatürk Eðitim ve Araþtýrma Hastanesi Patoloji Bölümünde tanýsý konulan ve Týbbi Onkoloji kliniðinde izlemi bulunan opere meme kanserli hastalar dahil edildi. Ýmmunhistokimyasal olarak nükleer p53 ekspresyonunun patolojik ve klinik prognostik göstergelerle iliþkisi deðerlendirildi.
BULGULAR: Çalýþmaya 395 meme kanseri tanýlý hasta dahil edildi. Ýkiyüzüç (%51,4) hastada p53 ekspresyonu saptandý. Moleküler alttiplere göre p53 boyanma yüzdeleri deðerlendirildiðinde p53 ekspresyonu en düþük oranda luminal A ve Luminal B-Her2 negatif grupta saptandý. Luminal A ve Luminal B-Her2 negatif grupta saptanan p53 boyanma yüzdeleri diðer alttipler ile karþýlaþtýrýldýðýnda istatistiki anlamlý farklýlýk olduðu saptanmýþtýr (p<0,05). p53 ekspresyonuna göre hastalar iki gruba ayrýldýðýnda, iki grup arasýnda saðkalýmlar açýsýndan fark saptanmadý (p>0,05). p53 ekspresyonu ile histolojik grad ve Ki-67 proliferasyonu arasýnda pozitif korelasyon, östrojen reseptör ekspresyonu ile negatif korelasyon saptandý (p<0,05).
TARTIÞMA ve SONUÇ: Çalýþmamýzda p53 ekspresyonunun kötü prognoz ile iliþkili olabileceði gösterilmiþtir. Mutant P53 proteinini hedefleyen tedaviler ile ilgili preklinik ve klinik çalýþmalarýn artmasý, immunhistokimyasal olarak p53 ekspresyonunun prognostik ve prediktif önemini ortaya çýkaracaktýr.