To evaluate survival among patients with urothelial carcinoma (UC) within the prostate in order to assess the impact of depth of tumour invasion as well as the importance of a concurrent bladder tumour.

We identified 201 patients who underwent radical cystectomy (RC) between 1980 and 2006 and were found to have UC involving the prostate. All specimens were re-reviewed by a genitourinary pathologist. Survival was estimated using the Kaplan-Meier method and compared with the log-rank test. Cox hazard regression models tested the association of clinicopathological variables with outcome.

In all, 93 patients had pTis disease in the prostate, 43 had pT2 tumours, and 66 patients were pT4a. The median follow-up was 10.5 years. The 5-year cancer-specific survival for patients with pTis, pT2, and pT4a prostate UC was 73%, 57%, and 21% respectively (P < 0.001). On multivariable analysis, higher prostate tumour stage (hazard ratio [HR] 2.09; P = 0.01), positive lymph node status (HR 2.09; P = 0.002), and concurrent ≥pT3 bladder cancer (HR 4.16; P < 0.001) were significantly associated with an increased risk of death from UC.

Among patients with prostatic UC involvement, depth of tumour invasion was significantly associated with cancer-specific mortality, validating the staging reclassification. Concurrent locally advanced bladder cancer also negatively impacted survival, suggesting the potential prognostic value of reporting a secondary tumour stage in such cases.