SEMINAL-VESICLE BIOPSY - ACCURACY AND IMPLICATIONS FOR STAGING OF PROSTATE-CANCER

Objectives. Seminal vesicle biopsy (SVB) is a new technique for detect ing the spread of prostate cancer to the seminal vesicles. A compariso n of findings following SVB in patients undergoing radiation therapy w ith pathologic findings following radical retropubic prostatectomy (RR P) was made to evaluate the accuracy of this test and its use in the s taging of prostate cancer. Methods. Four hundred nine patients with cl inically localized adenocarcinoma of the prostate gland were evaluated for treatment: 222 patients underwent SVB prior to radiation therapy and 187 patients underwent RRP. Clinical stages in patients undergoing SVB included Tla (1 patient), T1b (4), Tie (55), T2a (49), T2b (96), and T2c (37); RRP clinical stages included T1b (5 patients), Tie (48), T2a (57), T2b (66), and T2c (15). The Gleason scores in patients unde rgoing SVB were 2 to 4 in 50 men, 5 to 6 in 110 men, and 7 and greater in 62 men; the Gleason scores in patients undergoing RRP were 2 to 4 in 53 men, 5 to 6 in 94 men, and 7 and greater in 40 men. Prostate-spe cific antigen (PSA) values ranged from 1.3 to 190 ng/mL (median 10.75) in men undergoing SVB and ranged from 0.5 to 140.6 ng/mL (median 9.0) in men undergoing RRP. Results. The overall incidence of seminal vesi cle involvement as determined by the two techniques was the same. Semi nal vesicle involvement was found in 53 of 222 patients (15%) undergoi ng SVB and in 27 of 187 (14%) of the RRP specimens (P = 0.9). When the two groups were further divided by three prognostic categories (clini cal stage, PSA level, and grade), there was no difference in the incid ence of seminal vesicle involvement between the two methods, except in the patients with Gleason score of 4 or less. In these patients, 5 of 53 (9%) had seminal vesicle involvement in the RRP group, compared wi th none of the 50 men in the SVB group (P = 0.02). Disease that was no t organ confined was found in 69 of 187 prostatectomy specimens (37%). Of these patients, 27 of 69 (39%) had seminal vesicle involvement. Co nclusions, SVB is an accurate method of detecting seminal vesicle inva sion based on comparisons with radical prostatectomy findings. Its imp ortance lies in its ability to detect a large percentage of patients w ith non-organ-confined disease and in its use in modifying treatment p lanning accordingly. Copyright 1996 by Elsevier Science Inc.