Preoperative prediction of pathological tumor volume and stage in clinically localized prostate cancer: comparison of digital rectal examination, transrectal ultrasonography and magnetic resonance imaging.

Accurate preoperative staging is important for proper selection of patients for radical retropubic prostatectomy. Preoperative staging by digital rectal examination, transrectal ultrasound, magnetic resonance imaging (MRI), Gleason grade and prostate specific antigen was compared to pathological stage for 25 patients who underwent radical retropubic prostatectomy. The predictive value for tumor confinement was 36% by rectal examination, 37% by ultrasound and 30% by MRI. The predictive value for extracapsular disease was 100% by rectal examination, 83% by ultrasound and 66% by MRI. Preoperative determinations of tumor volume by any modality did not correlate with pathological tumor volume. Digital rectal examination, ultrasound and MRI clinically understage the disease in most patients but they may be reliable to predict extracapsular disease.