Overexpression of p53 protein in a high-risk population of patients with superficial bladder cancer before and after bacillus Calmette-Guérin therapy: correlation to clinical outcome.

Abstract

PURPOSE We have previously demonstrated that p53 overexpression is predictive of disease progression and survival in Ta, Tis, and T1 tumors. Instillation of Bacillus Calmette-Guérin (BCG) is now accepted to be the most efficient adjuvant therapy for superficial bladder carcinoma. The aim of this study was to determine if p53 status, assessed before and after intravesical BCG therapy, can predict clinical outcome in a high-risk population of patients with superficial bladder carcinoma. MATERIALS AND METHODS We examined 196 tissue specimens from 98 patients, obtained immediately before and after intravesical BCG therapy. The pretherapy population was composed of 22 Ta, 57 Tis, and 19 T1 tumors. After BCG, 66 specimens were TO and 32 had residual tumors. Nuclear p53 overexpression was analyzed in relation to time to disease progression and disease-specific survival. RESULTS The median follow-up duration was 44 months. The detection of nuclear p53 overexpression before BCG therapy did not predict response to BCG therapy. Pre-BCG p53 protein overexpression, response to BCG therapy, and pre-BCG stage were all independent markers of disease progression. In patients with residual disease after BCG therapy (nonresponders), multivariate analysis confirmed that posttherapy p53 overexpression was the only independent marker of disease progression. CONCLUSION In this high-risk population of patients with superficial bladder tumors, patients who have p53 nuclear overexpression in the tumor and stage T1 disease before BCG therapy are at high risk of disease progression. Furthermore, in the group of patients with residual disease after BCG therapy, p53 status is a better predictor of disease progression than post-BCG stage.