Role of systematic ultrasound-guided staging biopsies in predicting extraprostatic extension and seminal vesicle invasion in men with prostate cancer.

Purpose: To assess the presence of extraprostatic extension and seminal vesicle invasion in men with prostate cancer, we performed systematic staging biopsies targeting neurovascular bundles, seminal vesicles, and other extraprostatic tissues before the men underwent radical prostatectomy. We retrospectively evaluated the clinical efficacy of these systematic staging biopsies compared with digital rectal examination (DRE) and transrectal sonography (TRUS).

Methods: Two hundred forty-four candidates for prostatectomy who had a diagnostic biopsy Gleason score of 8 or higher and/or indications of extraprostatic extension (eg, seminal vesicle invasion) by DRE or TRUS underwent staging biopsies using an 18-gauge Tru-Cut needle under real-time TRUS guidance between June 1997 and March 2000. We determined the number of staging biopsy cores to be taken based on the Gleason score of the diagnostic biopsy as well as abnormal DRE and/or TRUS findings. The chi-square test was used to evaluate the statistical significance of differences.

Results: There were no complications of staging biopsy. In 75 (31%) of the 244 patients, results of the staging biopsies were positive. The clinical stage was upgraded by staging biopsy in 18 (24%) of these 75 patients. After the staging biopsies, 90 patients underwent radical prostatectomy. Among these 90 patients, staging biopsy specimens were positive for cancer in 20 (47%) of the 43 patients who received neoadjuvant therapy and in 1 (2%) of the 47 patients who did not receive neoadjuvant therapy. There were no false-positive staging biopsies in either group. Among the 90 patients who underwent radical prostatectomy, the false-negative rate for the prediction of organ-confined disease was 43% (30/69) for staging biopsies compared with 29% (10/34) for TRUS. The diagnostic accuracy of staging biopsies (67%; 60/90) was higher than that of DRE (52%; 47/90; p < 0.05) but lower than that of TRUS (79%; 71/90; p = 0.066).

Conclusions: Staging biopsies can reliably sample extraprostatic tissue, including the seminal vesicles and neurovascular bundles. Positive staging biopsy results can aid in the selection of treatment options and in the prediction of outcome for individual patients by providing definitive histologic confirmation of locally advanced disease. Conventional predictive variables for staging can be applied when the results of staging biopsies are negative.