Comparative study on the prevalence of clinically detectable prostate cancer in patients with and without bladder cancer.

Objectives: To investigate the prevalence of prostate cancer in patients with a past or present history of bladder cancer compared with age-matched control subjects in population-based screening for prostate cancer.

Methods: Between 1998 and 2000, 106 patients who were followed up in the outpatient clinic for bladder cancer (case cohort) and 1060 age-matched men who participated in screening for prostate cancer (control cohort) were enrolled in this study. Serum prostate-specific antigen (PSA) levels were measured for all participants, and all participants underwent digital rectal examination (DRE). The PSA distribution and prevalence rate of prostate cancer were compared between these two cohorts.

Results: The serum PSA levels were significantly greater in the case cohort than in the control cohort. The detection rate of prostate cancer was 12.3% (13 of 106) and 1.5% (16 of 1060) in the case and control cohorts, respectively. The biopsy compliance for those with abnormal PSA and/or DRE findings was significantly lower (31%) in the control cohort than in the case cohort (84%). If all those in the control cohort with abnormal PSA and/or DRE findings had undergone prostate biopsies, another 26 cases of prostate cancer might have been detected. The expected detection rate of prostate cancer in the control cohort was high at 4.0% (42 of 1060); however, this was still significantly lower than that in the case cohort.

Conclusions: Patients with a present or past history of bladder cancer could be a high-risk group for developing or having prostate cancer. Additional studies should be conducted to confirm this.