Statistical analysis of the factors influencing the recurrence of urinary bladder cancer after radical cystectomy

ABSTRACT

Objective To evaluate the risk factors influencing the recurrence of urinary bladder cancer; and to predict the probability of recurrence within two years after radical cystectomy. Patients and Methods Between 1986 and 1994; 857 patients were admitted at the Urology and Nephrology Center of Mansoura University; Egypt; for treatment of bladder malignancy by radical cystectomy. The number of male patients was 682 (80) versus 175 females (20) with a mean age of 49 years (range 18 - 90 years). The median follow-up period was 38 months (range 0.03-138 months). Histopathology revealed squamous carcinoma in 440 patients (51); transitional carcinoma in 223 patients (26); adenocarcinoma in 94 patients (11) and mixed (two or more) types in 100 patients (11.7). Most of the patients presented with advanced-stage disease (defined as P3 or P4) 611 patients (71) had stage P3; 68 patients (6) stage P4. Bilharzial ova were seen in 80of the specimens; while regional lymph nodes were involved in 16of the cases. Results Cancer-related mortality was encountered in 199 patients (23.2) and mortality from unknown causes in 54 patients (6.3). Fifty-five patients (6.3) were alive with recurrence. Univariate and multivariate analysis of the survival rates showed that lymph node involvement (P = 0.0000); tumor grade (P = 0.0017); pathological stage (P = 0.0008); sex (P = 0.0005); urinary diversion (P=0.0080) and histopathology (P=0.0253) significantly influenced the recurrence-free survival after radical cystectomy. The 5-year survival rate was 61.7; and the 5-year hazard rate was 48.3. Using the logistic regression model for estimating and predicting the probability of recurrence within two years after radical cystectomy; we found that only one variable (lymph node involvement) had a significant effect on the prediction of the probability of recurrence. Conclusion These findings suggest that positive lymph nodes; tumor grade; stage; sex; urinary diversion and histopathology of tumor cells are independent predictors of survival in patients with bladder cancer. Positive lymph nodes are the most important indicators for recurrence in general and especially for predicting the probability of recurrence within two years after radical cystectomy