THE ROLE OF TRANSRECTAL ULTRASOUND-GUIDED STAGING BIOPSY AND ANDROGENABLATION THERAPY PRIOR TO RADICAL PROSTATECTOMY

Radical prostatectomy is the most common therapy for localized prostat e cancer. Unfortunately, resection is associated with positive surgica l margins in 35-50% of cases. We report the use of ultrasound-guided s taging biopsies to stage tumors preoperatively with greater accuracy. We also report the use of androgen ablation therapy (AAT) as an adjunc t to radical prostatectomy in an attempt to downstage tumors preoperat ively and decrease the incidence of positive margins. Between 1 June 1 991 and 31 July 1992, 131 patients underwent radical prostatectomies, 119 of whom underwent AAT before surgery and 12 of whom did not. Speci mens were examined for the presence of positive surgical margins, extr acapsular extension, and perineural invasion. Cases pretreated with AA T had a 9.2% positive surgical margin rate compared with 33% in untrea ted subjects. Extracapsular extension was seen in 22 of 119 (18.5%) of AAT, and 5 of 12 (41.7%) of non-AAT, cases. Perineural invasion was n early 3 times less likely in AAT patients. Moreover, perineural invasi on was significantly less marked in AAT patients. We present a subset of 11 patients who were definitively proven as pathologic stage C canc er by transrectal ultrasound (TRUS)-guided needle biopsy. These cases had prostate cancer intermixed with fatty tissue and pigmented seminal vesicle epithelium, elements not found in the prostate. In this selec ted stage C subset, gland shrinkage, evidence of downstaging, and tumo r obliteration were seen after AAT. We conclude that TRUS-guided stagi ng biopsy can definitively stage prostate cancer as stage C when tumor is intermixed with extraprostatic elements, and AAT appears to decrea se the incidence of positive surgical margins by tumoral necrosis and selective perineural kill. We believe that these findings demonstrate the antitumor effects of AAT and deserve further scrutiny in a large r andomized clinical trial.