Transitional cell carcinoma involving the prostate with a proposed staging classification for stromal invasion.

Purpose: We investigated the effect on survival of transitional cell carcinoma of the prostatic urethra, ducts and stroma, and determined the difference between prostatic stromal involvement occurring via direct extension through the bladder wall versus stromal invasion arising intraurethrally.
Materials and Methods: Between August 1971 and December 1989, 489 men underwent radical cystoprostatectomy for transitional cell carcinoma, including 143 (29.2%) identified with prostate involvement by transitional cell carcinoma, in the cystectomy specimen. Patients were separated into 2 groups: 1-19 in whom the primary bladder tumor extended full thickness through the bladder wall to invade the prostate (classified as P4a) and 2-124 in whom prostate involvement arose from within the prostatic urethra.
Results: Five-year recurrence-free and overall survival rates were 25 and 21%, respectively, in group 1 versus 64 and 55%, respectively, in group 2. In the 124 patients in group 2 survival rates were similar for those with prostatic urethral tumors or carcinoma in situ and ductal tumors (no stromal invasion). Five-year overall survival rates without and with stromal invasion were 71 and 36%, respectively (p < 0.0001). Transitional cell carcinoma of the prostatic urethra or ducts does not alter survival predicted by primary bladder stage alone. Prostatic stromal invasion arising intraurethrally significantly decreases survival, which varies based on primary bladder stage (64.6% in stage P1, 30.8% in stages P2/P3a and 13.6% in stage P3b, p = 0.0001). P1 bladder tumors with prostatic stromal invasion arising intraurethrally had a significantly higher survival rate than P4a tumors (64.6 versus 21%, p = 0.0001). P3b bladder tumors with stromal invasion had a survival rate similar to that of P4a tumors (p = 0.78).
Conclusions: Prostatic urethral or ductal transitional cell carcinoma does not alter survival determined by primary bladder stage alone and it should not be classified as P4a. Prostatic stromal involvement arising intraurethrally significantly decreases survival predicted by primary bladder stage alone. P1 bladder tumors with prostatic stromal invasion arising intraurethrally have a significantly higher survival rate than P4a tumors and they should be separately classified as P1str. Muscle invasive (P2/P3a) bladder tumors with stromal invasion have a higher survival rate than P4a tumors (no statistical significance) and they should be designated separately (that is P2str). P3b bladder tumors with prostatic stromal invasion arising intraurethrally are indistinguishable from P4a tumors.