Use of combined apoptosis biomarkers for prediction of bladder cancer recurrence and mortality after radical cystectomy

Background Deregulation of apoptosis is a characteristic of human carcinogenesis. We aimed to investigate expression of the apoptosis markers Bcl-2, caspase-3, P53, and survivin and the association with oncological outcomes of patients treated by radical cystectomy and bilateral lymphadenectomy for urothelial-cell carcinoma of the bladder. Methods Bcl-2, caspase-3, P53, and survivin immunostaining was undertaken on serial tissue microarrays containing cores from 226 consecutive patients (median follow-up 36.9 months [IQR 13.3-79.0]). 200 bootstrap resamples with replacement were done to reduce overfit bias and for internal validation. Findings Expression of Bcl-2, caspase-3, P53, and survivin was altered in 73 (32%), 111 (49%), 120 (53%), and 141 (64%) patients, respectively. By univariate analysis, altered expression of Bcl-2, caspase-3, P53, and survivin were all associated with high probability of disease recurrence (hazard ratio 2.24 [95% CI 1.51-3.32], p < 0.001; 1.73 [1.16-2.59], p=0.007; 2.70 [1.77-4.12], p < 0.001; and 2.32 [1.48-3.63], p < 0.001) and disease-specific mortality (2.06 [1.33-3.18], p=0.001; 2.35 [1.48-3.73], p < 0.001; 3.23 [1.98-5.28], p < 0.001; and 2.64 [1.57-4.44], p < 0.001; respectively). Risk of recurrence and disease-specific mortality progressively grew with increasing number of altered biomarkers. By multivariate analysis, alteration of four markers was independently associated with high rates of disease recurrence (4.03 [1.23-13.16], p=0.021) and disease-specific mortality (6.84 [1.43-32.63], p=0.016). Addition of the number of altered markers to a model that included standard predictors significantly enhanced its predictive accuracy for disease recurrence and disease-specific survival. Interpretation Bcl-2, caspase-3, P53, and survivin have a cooperative effect on progression of bladder cancer. Assessment of combined apoptosis marker status and number of altered markers in patients treated by radical cystectomy provides prognostic information that could help to identify those at high risk for disease recurrence and mortality, who could benefit from early adjuvant treatment.