Prognostic Significance of Immunohistochemical Expression of p53 Gene Product in Operable Breast Cancer

Abstract

Purpose

The aim of this study was to investigate the prognostic significance of the expression of p53 gene product in operable invasive breast cancer by performing immunohistochemical analysis.

Materials and Methods

Between January 1993 and December 2001, 440 operable invasive breast cancer patients underwent immunohistochemical staining for p53, and we retrospectively analyzed these results together with the clinical outcomes.

Results

The overexpression of p53 was detected in 51.6% of the cases. The overexpression of p53 was inversely correlated with lymph node metastasis (p=0.005). The tumor size, tumor histology, histologic grade, hormonal receptor status and tumor stage were not related to the overexpression of p53. Multivariate Cox regression analysis indicate that lymph node metastasis, tumor size and the p53 expression were the significant prognostic factors for overall survival; lymph node metastasis, the estrogen receptor status and the p53 expression were the significant prognostic factors for relapse free survival. On the subgroup analysis, the p53 non-expressors showed better 7-year overall survival (92.7% vs. 76.7%, respectively, p=0.011) and relapse free survival (74.9% vs. 57.8%, respectively, p=0.032) than did the p53 overexpressors for the patients with lymph node metastasis. However, for the patients without lymph node metastasis, the survival rates were not different for both the p53 non-expressors and the p53 overexpressors.

Conclusion

Immunohistochemical staining of the p53 gene product was an independent prognostic factor for predicting survival of the lymph node positive invasive breast cancer patients.

Key words: Breast neoplasms, Prognosis, p53, Immunohistochemistry