Indications for preoperative seminal vesicle biopsies in staging of clinically localized prostatic cancer

To identify patients at high risk of extraprostatic seminal vesicle infiltration, in whom preoperative seminal vesicle biopsies should be performed.

We studied the relationship between extraprostatic seminal vesicle infiltration and the available preoperative data [age, clinical stage, prostate-specific antigen (PSA) level, number and site of positive prostatic sextant biopsies, Gleason score] in a total of 75 patients suffering from clinically localized prostatic adenocarcinoma who were candidates for radical prostatectomy.

The chi 2 test showed that the preoperative data most significantly correlated with extraprostatic seminal vesicle infiltration were the presence of positive basal biopsies (p < 0.001). The PSA level did not have any predictive value. The most discriminant preoperative parameter of the state of the seminal vesicles (analysis of variance on a univariate model) was the state of the basal prostatic biopsies. The importance of this parameter was confirmed by cluster analysis. Overall, the risk of extraprostatic seminal vesicle invasion was 0 (0/21 patients) when the 2 basal prostatic biopsies were negative, 10.25% (4/39 patients) when 1 of the 2 basal prostatic biopsies was positive and 73.33% (11/15 patients) when both basal prostatic biopsies were positive.

In a patient with clinically localized prostatic adenocarcinoma who is a candidate for radical prostatectomy, seminal vesicle biopsies are useless when basal prostatic biopsies are negative, regardless of the state of other preoperative parameters. When 1 or 2 basal prostatic biopsies are positive, seminal vesicle biopsies can improve the pretreatment pathological staging.