Diagnostic value of transrectal ultrasound in tumor staging and in the detection of incidental prostatic cancer.

To evaluate the accuracy of transrectal ultrasonography in staging and detection of prostatic cancer, a prospective study was initiated. In 466 patients transrectal ultrasonography was performed before transurethral resection, suprapubic adenomectomy, or radical prostatectomy. The findings were compared with the histopathologic results. In 160 of the 466 patients a carcinoma of the prostate was proven by histology. In 21 patients the cancer was an incidental finding after transurethral resection. In 133 of the 160 patients (83.1%) the tumor was detected by ultrasound prior to surgery. The analysis of the results revealed, however, great differences in the accuracy in the different tumor stages. In those patients where the tumor was confined to the prostate, the carcinoma was identified only in 37.5% of the cases. Especially prostatic cancer stage pT1a-b (incidental) was detected only in 3 out of 21 patients. Thus, it can be concluded that transrectal ultrasonography is not more sensitive than the rectal palpation for detection of prostatic cancer stage T1a-b.