Analysis of Apical Soft Tissue Margins During Radical Retropubic Prostatectomy

PURPOSE: We determine the use of information gained with intraoperative biopsy and frozen section analysis of the apical soft tissue margin during nerve sparing radical retropubic prostatectomy. MATERIALS AND METHODS: A separate 2 to 3 mm. circumferential biopsy was obtained from the apical soft tissue margin, and was sent for frozen and permanent section analysis during radical retropubic prostatectomy in 95 men with clinically localized adenocarcinoma of the prostate. A single pathologist examined the surgical and apical soft tissue margin specimens for evidence and extent of benign or malignant prostate tissue. Urinary continence was evaluated at catheter removal and 3 months postoperatively. RESULTS: Of the patients 26% had positive surgical margins, of which 64% were positive apical margins. Permanent section of the apical soft tissue biopsy revealed no prostate in 39%, benign prostate in 54% and prostate cancer in 7% of patients. Because of the frozen section finding of adenocarcinoma in 3 patients, the apical soft tissue margin was further resected until the specimen was negative for malignancy. The apical soft tissue margin was the only positive margin site in 2 of these 3 patients. Positive surgical and apical margins, and percent tumor volumes greater than 26% on prostatectomy specimen had a significantly higher likelihood for positive apical soft tissue margins. The pathological finding of a positive apical margin on the surgical specimen had sensitivity, specificity, and positive and negative predictive values of 57%, 86%, 25% and 96%, respectively, for detecting prostate cancer on the apical soft tissue biopsy. Of the apical soft tissue biopsies 54% contained an element of benign prostatic tissue, although 92% of them contained benign tissue in less than 25% of the total specimen. Mean continence score in the men with and those without benign prostate tissue on apical soft tissue biopsy was 15.6 and 14.4, respectively (p = 0.15). The percent of men who required no protective pads for urinary continence at 3 months was 53% and 65% for those who had no prostate and those who had benign prostate tissue, respectively, in the apical soft tissue margin. CONCLUSIONS: Excising and submitting an additional 2 to 3 mm. of apical soft tissue margin for permanent section analysis after prostate removal during radical prostatectomy represent an effective method for decreasing residual prostate tissue. Attempts at maximizing urethral length when dividing the prostato-urethral junction likely increases the chance of leaving residual prostate without improving continence.