[Results of a series of transrectal ultrasound guided biopsy of the prostate in 6000 patients. Part I: pathology, digital rectal examination, transrectal ultrasound, and PSA].

Objectives: To analyze the results of transrectal ultrasound (TRUS) guided biopsy of the prostate in 6000 patients, and their relation to common-use clinical parameters.

Methods: We collected PSA, digital rectal examination, TRUS characteristics, and pathology report in a data- base including 6000 patients who underwent sextant TRUS biopsy from 1994 to December 2002. 861 of them underwent more than one biopsy, accounting for a total of 7127 biopsies. Sextant biopsy with samples from the most lateral portions of the prostate was the standard procedure so that they included peripheral zone only. We analyze pathological results and their relation with clinical variables.

Results: Total percentage of cancer in biopsy samples was 42.6%, with 39.1% in the first biopsy. Overall, repeated biopsies resulted in a 3.5% diagnostic yield increase. PIN or focal glandular atypia were detected in 2.0% and 2.1% of the cases respectively. The percentage of patients with Gleason score =<6 increased from 41.8% in the first biopsy to 70% in the third. Similarly, single core involvement increased from 21.% to 65%. Digital rectal examination and presence of hypoechogenic nodules specificity were 82.6 and 78.2% respectively. The incidence of prostate cancer with PSA between 4 and 10 ng/ml was 29.6%, 16.7% in those with PSA lower than 4 ng/ml.

Conclusions: TRUS biopsy of the lateral prostatic areas offers a good diagnostic yield in comparison with most series of extensive biopsies. The sensitivity of TRUS has decreased but it maintains a high specificity which should not be forgotten when planning the TRUS strategy