Comparison of ultrasound-guided biopsies and prostatectomy specimens: predictive accuracy of Gleason score and tumor site.

OBJECTIVE

To critically evaluate the accuracy of sextant biopsies in predicting Gleason score and the site of tumor location in patients with clinically localized prostate cancer treated by radical perineal prostatectomy.

METHODS

The case records of 289 patients with clinically localized prostate cancer who underwent radical perineal prostatectomy were reviewed, comparing the Gleason score and tumor site location as determined by sextant ultrasound-guided core biopsies with the Gleason score and tumor distribution within the surgical specimens. The prostatectomy specimens were further characterized by extent of disease as organ-confined, specimen-confined or margin-positive.

RESULTS

The Gleason score was identical in 126 (43.5%) patients. An upgrading in the surgical specimen occurred in 118 (40.8%) cases, a downgrading in 43 (14.8%). Overall, 193 (66.7%) patients had a unilateral positive biopsy, while 96 (33.2%) patients had bilateral positive biopsies. Sixty-four (33.1%) patients with a unilateral positive biopsy had cancer confined to one side of the gland, while 127 (65.8%) showed bilateral disease; 142 (73.5%) patients had organ-confined tumors versus 51 (26.4%) patients with capsular penetration. In the 96 patients with bilateral positive biopsies, 64 (66.6%) patients had intracapsular cancer versus 32 (33.3%) patients with either specimen-confined or margin-positive disease. The overall rate of positive margins was 14%. Fifty-one (61.4%) of the 83 patients with non-organ-confined disease had posterolateral capsular penetration in the region of the superior pedicle of the neurovascular bundle, while 28 (33.7%) patients had apical capsular penetration, in the region of the inferior neurovascular pedicle.

CONCLUSIONS

The ability of sextant ultrasound-guided biopsies to estimate the pathological grading is satisfactory: when we consider a difference of +/- 1 in the final Gleason score, the overall correlation is 80%. In 66% of the cases, sextant biopsies predicted unilateral disease when bilateral disease existed. A unilateral positive biopsy does not predict unilateral disease.