Repeat transrectal prostate biopsies in diagnosing prostate cancer

Patients with negative prostate biopsy and persistent suspicion of prostate cancer (PCa) can pose a serious diagnostic problem. The AIM of our study was to determine the frequency of PCa found on repeat prostate biopsy and the factors leading to higher possibility of cancer positive histological result.

We studied retrospectively 113 patients (82 from University Clinic, Jena, Germany and 31 from Department of Urology, Plovdiv, Bulgaria) with initial negative biopsy for cancer who underwent repeat biopsies. The patients were examined between January 1999 and May 2010. The target group included patients with Prostate Specific Antigen (PSA) level lower than 12.5 ng/ml and without suspicious finding on digital rectal examination (DRE). Different biopsy schemes were used in the initial and the following biopsies, depending on patient age and total prostate volume.

Overall PCa detection rate was 22.1% (25 of 113). The repeat biopsy found PCa in 15.9% (18 of 113). In patients with 3 biopsies the PCa detection rate was considerably lower--only 8.6% (3 of 35). PCa was found in only 1 patient of 18 (5.5%) who underwent four or more biopsies. Transurethral resection of the prostate (TURP) was performed in 15 patients with at least two previously negative biopsies. The pathohistological examination of the resected tissue showed PCa in 3 of the patients (20%).

The interval between biopsies is not a significant predictive factor for positive prostate biopsy. The chance for detecting PCa after the second negative transrectal biopsy procedure is low. Therefore, TURP can be used as an alternative procedure to harvest adequate tissue material for pathologic examination, especially in patients with obstructive voiding symptoms.