To investigate the relationship between prostate-specific antigen (PSA) level and tumour volume for incidental adenocarcinoma of the prostate found in cystoprostatectomy (CP) specimens, and to analyse the incidence of clinically significant prostate cancers in CP specimens and the biochemical recurrence of incidental prostate cancers on short-term follow up.PATIENTS AND METHODS
Complete data from 97 of 105 prostates from CP specimens were available. Prostates were thoroughly analysed and sectioned at 2 mm intervals. PSA levels and the findings at digital rectal examination before surgery were obtained prospectively. None of the patients had any evidence of prostate cancer before CP.RESULTS
Incidental prostate cancer was detected in 58 of 97 (60%) of the CP specimens; of these, 31 (53%) were significant according to the definition of Stamey et al. There was a weak correlation between tumour volume and PSA level, weighted solely by the four larger-volume cancers. The median PSA level for patients with and without prostate cancer was not significantly different (3.1 vs 1.1 ng/mL, P = 0.06). The follow-up of the 35 patients alive with prostate cancer showed four PSA recurrences (PSA >0.02 ng/mL) with one distant metastasis after a median follow-up of 3 years. None of the patients with insignificant tumours developed biochemical recurrence.CONCLUSIONS
The weak correlation between PSA level and tumour volume in these patients supports the argument that PSA is largely produced by benign prostatic hyperplasia and is therefore a poor screening tool for asymptomatic healthy men. Most incidental prostate cancers in CP specimens are significant, contrary to previous analyses, but have little practical importance in terms of oncological outcome.