Pronostic Value of The Expression of Mutant p53 and EGFR mRNA in Transitional Cell Carcinoma of the Bladder

Oh, Bong Ryoul; Sim, Jae Hong; Park, Chang Soo; Ryu, Soo Bang; Park, Yang Il

Abstract

PURPOSE: We evaluated the correlation between the clinical outcome and the expression of p53 protein and EGFR mRNA in bladder cancer.
MATERIALS AND METHODS
Sixty seven patients with transitional cell carcinoma of the bladder (40 patients with superficial cancer and 27 patients with invasive cancer) and 10 persons with normal urothelium were included in our study. We examined the overexpression of p53 protein by immunohistochemical analysis and EGFR by in situ mRNA hybridization. Both expression were compared with the known factors of prognosis.
RESULTS
Mutant p53 protein was overexpressed in 43.3% of transitional cell carcinoma cases and undetectable in normal urothelium. The positive staining of EGFR mRNA was observed in 30% of normal urothelium and 100% of transitional cell carcinoma of bladder. p53 overexpression was related to the degree of differentiation, but not with the stage and the recurrence of superficial cancers. Progression to invasive cancer occurred in 4 patients with superficial cancer and all of them showed p53 protein overexpression, which had statistical significance (P<0.05). p53 positivity in invasive cancer was not related to the poor survival and strong expression of EGFR mRNA. The positive staining of EGFR mRNA was also not related to stage, grade, recurrence and survival. When we combined positivity of p53 and EGFR mRNA, we observed that the subset of patients with strong expression of EGFR mRNA and positive expression of p53 also had no different survival.
CONCLUSIONS
These results suggest that mutant p53 protein does not seem to be a prognostic marker for the recurrence of superficial cancer and survival but may be a marker for progression of superficial cancer to invasive cancer.