Pathological correlation between needle biopsy and radical prostatectomy specimen in patients with localized prostate cancer

Objective: This study aims to evaluate the accuracy of transrectal ultrasound (TRUS) guided prostate biopsies in predicting pathological grading and tumour distribution in the final pathological specimen of patients who underwent radical prostatectomy for clinically localized prostate cancer. The study ultimately aims to gain more understanding of the pathological behaviour of prostate cancer and the limitations of the currently available diagnostic and prognostic tools. Material and Methods: We reviewed the records of 100 patients with localized carcinoma of the prostate diagnosed by TRUS-guided prostate biopsy and treated with radical retropubic prostatectomy, comparing tumour laterality and Gleason score in core biopsies with tumour distribution and Gleason score of the surgical specimen. We then correlated both results to diagnostic and prognostic variables such as prostate specific antigen (PSA) values and surgical margins. Results: All 44 patients with bilateral disease on needle biopsy had bilateral disease on final pathology, with 15 of these patients (34%) having positive margins. Of the 56 patients with unilateral disease on biopsy, 37 (66%) had bilateral disease on final pathology; however, only 4 of them (7%) had positive margins (p < 0.001). Median Gleason score on final pathology was upgraded to 7, compared with a median score of 6 on biopsies. Stratifying patients to 2 groups based on their PSA level (group 1: PSA < 10 ng/mL, 72 patients; group 2: PSA > 10 ng/mL, 28 patients), revealed that 57 patients (79%) in group 1 and 24 patients (85%) in group 2 had bilateral disease. In addition, 13 patients (18%) in group 1 and 6 patients (21%) in group 2 had positive margins. Conclusions: Sixty-six percent of patients with unilateral disease on needle biopsy had bilateral disease on final pathology, but this does not increase their rate of having positive margins. Gleason score is upgraded from 6 to 7. PSA did not seem to affect laterality of disease in patients selected for radical prostatectomy.