Immunohistochemical detection of p53 protein expression as a prognostic indicator in Wilms tumor

Background. Mutations of the tumor suppressor gene p53 are commonly found i n several kinds of human cancer. In some types of neoplasms, accumulation o f p53 protein has been reported to correlate with more aggressive clinical behavior. The role of p53 expression in Wilms tumors (WT) is not clear yet, but most studies have confirmed its correlation with anaplasia and advance d stage disease. Procedure. Ninety-seven WT were evaluated for p53 expressi on by immunohistochemistry in formalin-fixed parafin-embedded tissue and co rrelated with outcome. Tumors were classified as p53-Negative (p53-N) when no positivity was observed or only few cells showed weak positivity (0/1+) and p53-Positive (p53-P) when there was a diffuse and strong nuclear positi vity (2+/3). Results. p53-P was detected in 13 out of 97 tumors and was ass ociated with disease relapse (39 vs .17%; P = 0.06) but not with anaplasia. Among p53-N patients only 5% had metastatic disease compared with 31% of t he p53-P sample. (P = 0.038). Overall survival was 94% for patients with p5 3-N vs. 85% for patients with p53-P at 1 year (P = 0.34). Conclusions. p53 expression in Wilms tumor detected by immunohistochemistry seems to be asso ciated with advanced disease and relapse. (C) 2001 Wiley-Liss, Inc.