Poster session 6: Prostate cancer| Volume 8, ISSUE 8, P690, September 2009

C97 Comparison of clinical and pathological features between prostate cancers detected by the first biopsy and by re-biopsy with an extended scheme

      Introduction and Objectives

      To compare clinical and pathological characteristics between patients undergoing radical prostatectomy for clinically localised prostate cancer (PC) detected in the first prostate biopsy and those detected in the re-biopsy with a 24 core extended scheme.

      Material and Methods

      Overall, 256 patients treated with radical prostatectomy between January 2005 and December 2007 were eligible for analysis. PC was detected by the first prostate biopsy with at least 6 to maximal 12 cores (mean 8.6) in 201 patients (group 1), and in 55 men by extended re-biopsy with 24 cores (group 2), respectively. Rebiopsy rate ranged between 1 and 8 (mean 2.5). Clinical and pathological parameters were compared between both groups using Student's t-test and Chi-squared test. Cohen's kappa (k) coefficient was used to measure the agreement of Gleason scores of the fine-needle-core biopsies and radical prostatectomy specimens.


      Mean age was similar with 61.1 years of group 1 and 61.7 years of group 2 (p = 0.633). The median serum PSA and PSA ratios were 5.9 ng/ml and 11.1% in group 1 as well as 7.8 ng/mL and 10.9% in group 2 (p = 0.372 and p = 0.596), respectively. A suspicious digital rectal examination (DRE) was assessed in 33.6% of group 1 and 10.6% of group 2 (p = 0.002). Stages pT2, pT3a and pT3 b were assessed in 77%, 15.5% and 7.5 of group 1 and 85.3%, 9.1% and 5.5% of group 2 (p = 0.618), respectively. Gleason score of ≤ 6, 7 and ≥8 in prostatic biopsy specimens were diagnosed in 70.2%, 24.0% 5.8% in group 1 and 69.2%, 23.1% and 7.7% in group 2 (p = 0.874). The corresponding Gleason scores of the radical prostatectomy specimens were 34.5%, 56.5% and 9.0% in group 1 and 39.6%, 56.6% and 3.8% in group 2 (p = 0.415). Agreement between biopsy and prostatectomy Gleason Score expressed by Cohen's kappa, revealed coefficients of 0.250 in group 1 and 0.356 in group 2. More specifically, concordance was higher in group 2 with 51.9% vs. 45.7% in group 1. Biopsy Gleason score showed a more frequent undergrading in group 1 with 47.2% vs. 34.6% in group 2, whereas overgrading was more frequently observed in group 2 with 13.5% vs. 7.1% in group 1.


      The comparison revealed 2 relevant differences. Firstly, the concordance between Gleason score of needle biopsy and radical prostatectomy specimens was distinctly higher in the extended re-biopsy cohort. And secondly, patients with PC detected by a 24 core extended-re-biopsy scheme presented with a significantly lower rate of suspicious DRE. Hence, the clinical impact of routinely performed DRE in patients after negative prostate biopsy appears small.