Incidental prostate cancer in patients with muscle-invasive bladder cancer who underwent radical cystoprostatectomy.

Objectives: The aim of this study was to analyze the features of incidentally detected prostate cancer (PCa) in radical cystoprostatectomy (RCP) specimens to determine their pathological characteristics and clinical significance.

Methods: In this retrospective study, we reviewed the clinical and pathological records of 431 consecutive patients with muscle-invasive bladder cancer who underwent RCP at Hirosaki University. Of these, we focused on 237 male patients with prostate-specific antigen (PSA) measurements and digital rectal examinations (DRE) that were recorded prior to the RCP. Significant PCa was defined as a tumor with a Gleason 4 or 5 pattern, pathological T3 or higher stage, lymph node involvement or three or more multifocal lesions within the prostate specimen. We compared clinically significant and insignificant PCa.

Results: In this study, a total of 43 patients (18.1%) were diagnosed with incidental PCa via RCP specimens. Age, preoperative PSA levels and pathological T stage in patients with clinically significant PCa were considerably higher than in those with insignificant cancer. Apical involvement was found in 16 patients, including 11 of those with clinically significant PCa. By the end of the follow-up period, none of the enrolled patients had a biochemical recurrence after surgery or died from PCa.

Conclusion: According to our findings, preoperative risk factors were not reliable enough to accurately predict clinically significant PCa. Although there was no biochemical relapse or clinical recurrence of PCa in this study, the potential oncologic risk of prostate-sparing RCP must be considered.