Depth and origin of prostatic involvement by urothelial carcinoma: prognostic significance and staging interpretation.

OBJECTIVE To investigate the prognostic significance of prostatic involvement by bladder urothelial carcinoma using the new 2009 TNM staging system. METHODS From 1993 to 2008, 77 consecutive men who were clinically and/or pathologically diagnosed with bladder cancer underwent radical cystectomy. Patients were classified into several groups, according to the presence, extent and invading pathway of prostatic involvement by urothelial carcinoma, whether there was stromal or non-stromal involvement, and whether there was contiguous or non-contiguous involvement. Cause-specific survivals were calculated in each group and they were compared. RESULTS Prostatic involvement was observed in 23 (30%) patients: 10 had non-contiguous non-stromal involvement, 5 had non-contiguous stromal involvement and 8 had contiguous stromal involvement. Patients with stromal involvement (both contiguous and non-contiguous) showed significantly shorter cause-specific survival compared with those without prostatic stromal involvement (P= 0.002). The survival of patients with contiguous prostatic stromal involvement was similar to that of patients with non-contiguous prostatic stromal involvement (P= 0.79). Multivariate analysis showed that prostatic stromal involvement (both contiguous and non-contiguous) (hazard ratio, 8.4; P< 0.001), lymph node involvement (hazard ratio, 4.4; P= 0.016) and perivesical fat involvement (hazard ratio, 3.8; P= 0.029) were predictive of cause-specific survival. CONCLUSIONS The depth of prostatic involvement has a significant impact on survival for patients with bladder urothelial carcinoma; however, whether its origin is contiguous or non-contiguous does not appear to be important.