Objectives: To evaluate the correlation between the overexpression of mutant protein p53 and disease recurrence and progression in patients treated with bacillus Calmette-Guérin (BCG) intravesical therapy for T1G3 bladder cancer.
Methods: We analyzed the outcome of 29 consecutive patients treated for T1G3 bladder tumor with transurethral resection. Patients previously treated for a bladder tumor, those who underwent incomplete resection, and those in whom no assessment of the muscle cell layer was possible were excluded from the study. p53 overexpression was determined using monoclonal p53-DO7 antibody, with a 20% cutoff for definition of positivity. After the initial transurethral resection, all patients were treated with Pasteur BCG (75 mg in 50 mL saline), weekly for 6 weeks. The correlation between p53 overexpression and disease recurrence and progression was assessed by the Fisher exact test.
Results: The median follow-up was 36.7 months (range 1 to 108). Of the 29 patients, 18 (62.1%) were p53 positive and 11 (37.9%) were p53 negative. Both groups were similar according to age, tumoral substage (T1a/T1b), association with carcinoma in situ, multifocality, and length of follow-up. The recurrence rate was 54.4% in the p53-negative group versus 38.9% in the p53-positive group (P = 0.47). The progression rate was 18.2% in the p53-negative group versus 33.3% in the p53-positive group (P = 0.67).
Conclusions: These findings suggest that overexpression of p53, as determined immunohistochemically, has no predictive value for recurrence and progression in T1G3 bladder cancers treated with intravesical BCG.