How and When to Take Prostate Biopsies

Extended 12-core prostate biopsy increases both the detection of prostate cancer and the accuracy of Gleason score

OBJECTIVE

To evaluate the effect of extended 12-core prostate biopsy in improving the detection rate of prostate cancer and increasing the accuracy of Gleason score.

METHODS

This study included 113 patients who underwent TRUS-guided lateral sextant biopsy (group I) and 176 patients who underwent extended 12-core biopsy (group II). Inclusion criteria for prostate biopsy were elevated serum PSA levels (>3.0 ng/ml) and/or suspicious digital rectal examination (DRE).

RESULTS

Clinical characteristics were similar in both groups. Cancer was detected in 28 (24.8%) and 64 (36.4%) patients in group I and II respectively, chi2=4.26, p=0.039. Among patients with cancer in group I, 14 were treated by radical prostatectomy (RP). The median Gleason sum was 6 (range 3-8) and 7 (range 5-9) for needle and prostatectomy specimens respectively. There was an agreement between the biopsy and prostatectomy Gleason sum in 7 (50%) patients while the biopsy Gleason sum was lower in 7 (50%) cases. Among patients with cancer in group II, 27 were treated by RP. The median and the range of Gleason sum was the same for needle and prostatectomy specimen (median 6, range 4-9). There was an agreement between the biopsy and prostatectomy specimen in 23 (85.2%) patients while the biopsy sum was lower than prostatectomy in 4 (14.8%) patients. The agreement between the biopsy and prostatectomy specimen was significantly higher in group II (82.5%) than group I (50%), Fisher's Exact Test, p=0.026.

CONCLUSION

Extended 12-core prostate biopsy significantly increases both the detection rate of prostate cancer and the accuracy of biopsy Gleason score.