Elevated serum prostate specific antigen levels in conjunction with an initial prostatic biopsy negative for carcinoma: who should undergo a repeat biopsy?

OBJECTIVE: To determine the outcome of repeated prostatic biopsies in men attending with suspected prostate cancer but an initial negative biopsy. PATIENTS AND METHODS: Patients who had undergone two or more transrectal ultrasonography (TRUS)-guided prostate biopsies were identified from the Hospital Information Support System database. Indications for TRUS were a raised prostate-specific antigen (PSA) level (>4.0 ng/mL), with or without an abnormal digital rectal examination (DRE). Sextant prostate biopsies plus biopsies of any suspicious hypoechoic area or area of DRE abnormality were obtained for histology. Forty-eight patients underwent repeat TRUS-guided prostatic biopsies (mean age 67.5, sd 7. 25, range 53-82 years).
RESULTS: The mean (sd, median, range) PSA level was 16.9 (13.5, 11.6, 5.2-61.8) ng/mL. Fifteen patients (31%) had carcinoma on repeat biopsy, 11 after the second and four after a third biopsy. The positive repeat biopsy rate was 24% where the PSA level was 4.0-9.9 ng/mL, 33% if the level was 10.0-19.9 ng/mL and 39% if it was >/=20.0 ng/mL. There was no significant difference in age or initial PSA concentration between those men with positive and those with negative repeat biopsies. However, patients with cancer had significantly higher PSA levels before repeat biopsy than at first biopsy (P=0.0043) and had greater PSA velocities than had patients with no diagnosis of cancer (P=0.0067).
CONCLUSION: Where sufficient clinical suspicion exists, despite an initial negative biopsy, repeat TRUS-guided prostate biopsies should be carried out to exclude carcinoma of the prostate.