| Popis: |
Radical prostatectomy is the most common therapy for localized prostate cancer. Unfortunately, resection is associated with positive surgical margins in 35-50% of cases. We report the use of ultrasound-guided staging biopsies to stage tumors preoperatively with greater accuracy. We also report the use of androgen ablation therapy (AAT) as an adjunct to radical prostatectomy in an attempt to downstage tumors preoperatively and decrease the incidence of positive margins. Between 1 June 1991 and 31 July 1992, 131 patients underwent radical prostatectomies, 119 of whom underwent AAT before surgery and 12 of whom did not. Specimens were examined for the presence of positive surgical margins, extracapsular extension, and perineural invasion. Cases pretreated with AAT had a 9.2% positive surgical margin rate compared with 33% in untreated 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 nearly 3 times less likely in AAT patients. Moreover, perineural invasion was significantly less marked in AAT patients. We present a subset of 11 patients who were definitively proven as pathologic stage C cancer 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 selected stage C subset, gland shrinkage, evidence of downstaging, and tumor obliteration were seen after AAT. We conclude that TRUS-guided staging biopsy can definitively stage prostate cancer as stage C when tumor is intermixed with extraprostatic elements, and AAT appears to decrease 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 randomized clinical trial. |
