Is stage pT4a (D1) reliable in assessing transitional cell carcinoma involvement of the prostate in patients with a concurrent bladder cancer? A necessary distinction for contiguous or noncontiguous involvement

Purpose: A series of patients with concurrent transitional cell carcinoma involvement of the prostate and bladder is reviewed to define the impact of prostate involvement pathways and the degree of prostate invasion on survival rate. Materials and Methods: A total of 72 patients who underwent radical cystectomy for pathological stage pT4a (D1) cancer was divided into contiguous-stage pT4a, transitional cell carcinoma of the bladder extended into the prostate through the bladder wall and noncontiguous-stage pT4a simultaneous transitional cell carcinoma of the prostate and bladder carcinoma that did not directly infiltrate into the prostate through the bladder wall. In the latter group the degree of prostate invasion was classified as urethral mucosal involvement, ductal/acinar involvement, stromal invasion and extracapsular extension. The survival rate was estimated by the Kaplan-Meier and Cox proportional hazards methods. Comparisons between curves were performed by univariate log rank and multivariate L-ratio tests. Results: The overall 5-year survival rate for stage pT4a was 21.5% (median followup 64 months). Furthermore, 46% and 7% of patients in noncontiguous and contiguous pT4a groups, respectively, were estimated to be alive (p <0.000). Those with positive nodes experienced a poor outcome in both groups. Of patients with noncontiguous pT4a stage 100% with urethral mucosal involvement, 50% with ductal/acinar involvement and 40% with stromal invasion were estimated to be alive. The major prognostic factors were bladder tumor stage, nodal involvement and degree of prostate invasion. Conclusions: The invasion pathways of the prostate in patients with transitional cell bladder carcinoma have a statistically significant prognostic role. Contiguous and noncontiguous involvements are 2 distinct clinicopathological features and they should not be included in the same stage. In the noncontiguous stage pT4a group bladder and prostate transitional cell carcinoma should be separately staged, and prostate involvement also should be staged according to invasion degree.