Immunohistochemical Detection of p53 Protein Expression as a Prognostic Factor in Wilms Tumor

Abstract

Introduction. Histological typing, especially the evidence of anaplasia and stage of the tumor are two major prognostic indicators in Wilms tumor, but some genetic factors have recently been noted. Mutations in TP53, which is a tumor suppressor gene, have been demonstrated to be associated with poor prognosis in some malignancies. There are also few studies which have confirmed the correlation between p53 protein overexpression and advanced course in Wilms tumor. This study was conducted to determine the correlation p53 immunoexpression and prognosis and outcome of Wilms tumor.

Materials and Methods. The overexpression of p53 in 44 specimens of children (26 boys and 18 girls) with Wilms tumor (median age, 36 months; range, 4 to 96 months) was assessed in Mofid Children's Hospital, Tehran, Iran. The overexpression of p53 was determined by immunohistochemistry with antihuman p53 antibody.

Results. A positive immunostaining for p53 was detected in 24 of the 44 cases (54.7%). The grade of the tumor and anaplasia were associated with p53 positivity, but there was no association of p53 with the tumor stage. In comparison to p53 negatives, week-moderate and high p53-expressing tumors had significantly decreased the overall survival (hazard ratio, 3.75 and 8.61; P = .05 and P = .01, respectively).

Conclusions. Overexpression of p53 protein in Wilms tumor is an indicator of poor pro gnosis, because it is correlated with unfavorable histology tumors and a shorter survival period.