CORRELATION BETWEEN P53 OVER-EXPRESSION AND RESPONSE TO BACILLUS-CALMETTE-GUERIN THERAPY IN A HIGH-RISK SELECT POPULATION OF PATIENTS WITH T1G3 BLADDER-CANCER

Purpose: The aim of this study was to determine if p53 status, assesse d before intravesical bacillus Calmette-Guerin (BCG) therapy, can pred ict clinical outcome in a high risk population of patients with stage T1, grade G3 bladder cancer and if it can be used to select patients r esponsive to therapy. Material and Methods: After complete transurethr al resection 35 patients with T1G3 bladder carcinoma received 6 weekly instillations of BCG and nonresponsive patients received a second cou rse. After treatment cystoscopy and randomized biopsies of the bladder mucosa were performed. Pathologists had sufficient material to perfor m immunomarking in 25 cases using the peroxidase-antiperoxidase techni que viith antiprotein monoclonal antibody p53. The results were expres sed in percentage of marked nuclei. We established 5% increment thresh olds from 0 to 60%. Contingent tables were established, and chi-square and Fisher's exact test were performed for each 5% threshold. Results : Median followup was 51.3 months (range 25 to 144). Of the 25 patient s 8 (32%) did not respond to BCG therapy and 17 (68%) did. Immunomarki ngs were not statistically different between BCG responsive and nonres ponsive patients for 0, 5, 10, 20, 35, 40, 45, 55 and 65 thresholds. C hi-square and Fisher's exact test were 0.91 and 0.83, 0.40 and 0.20, 0 .58 and 0.29, 0.96 and 0.81, 0.80 and 0.88, 0.67 and 0.73, 0.91 and 0. 83, 0.80 and 0.38, 0.69 and 0.32, respectively. Conclusions: Our resul ts indicate that the percentage of p53 immunomarked cell cannot curren tly be used to predict clinical response to BCC therapy and, therefore , p53 over expression is not a viable indicator of T1G3 recurrence whe n using this treatment.