Detection of prostatic carcinoma: the role of TRUS, TRUS guided biopsy, digital rectal examination, PSA and PSA density.
The purpose of this study was to evaluate the efficacy of various diagnostic tests including transrectal ultrasound (TRUS), TRUS guided biopsy, digital rectal examination (DRE), prostate specific antigen (PSA), and prostate specific antigen density (PSAD) in detecting prostatic carcinomas. One hundred and thirty-four men underwent TRUS guided random, or directed and random sonographic biopsies of the prostate. The mean age was 64.67 (range, 31- 88) years. Indications for biopsy were abnormal findings suggesting prostatic carcinoma on DRE or increased levels of PSA, defined as 4.0 ng/ml or greater in a monoclonal antibody assay. PSAD was calculated by dividing the serum PSA in ng/ml to the volume of the entire prostate in cm3. The biopsy results were grouped as benign, malign and, prostatitis. The patients were also divided into three groups according to their PSA values. Of the 134 patients evaluated, 31 (23.1%) had prostate adenocarcinoma, 89 (66.4%) had benign prostatic tissue, hyperplasia or prostatic intraepithelial neoplasia, and 14 (10.4%) had prostatitis. The mean PSA and PSAD of the carcinoma group were significantly higher than those of the noncancer group. In the group of patients with PSA levels between 4 and 10 ng/ml, abnormal TRUS or DRE increased cancer detection rate, where neither PSA nor PSAD was capable of discriminating the patients with and without cancer. PSAD did not prove to be superior to the other diagnostic tests in this study. We recommend biopsy when either TRUS or DRE is abnormal in patients with PSA levels between 4 and 10 ng/ml. In the patients with PSA levels greater than 10 ng/ml, biopsy is indicated whatever the findings on TRUS or DRE are, since cancer detection rate is high.