[Peroperative biopsy of the sub-apical urethra during prostatectomy for cancer]

Between 35 to 45% of radical prostatectomies (RP) will show positive margins and approximately 50% of patients with positive margins will progress following RP. Peroperative diagnosis of positive margin possibly can improve the currability of RP. We report here the incidence and management of positive urethral margins diagnosed by frozen sections during radical prostatectomy.

Frozen sections were performed systematically to analyse the surgical margins during 130 RP performed for localized prostate cancer from january 1989 to december 1993. Peroperative analysis of distal (urethral) and proximal (bladder neck) margins, as well as posterior (Denonvilliers fascia) margins, and every surrounding tissue that was macroscopically abnormal were performed.

Analysis of the distal margins showed no prostatic gland in 68 cases (52%), normal prostatic glands in 56 cases (43%) and neoplastic prostate glands in 6 cases (5%). Further urethral sections with frozen section analysis were performed in 62 cases until the distal margin was free of prostatic glands. Three out of six patients with positive urethral margins had another positive margin that was excised as well. Five out of six patients with positive urethral margins were pT3, NO, MO and one pT2, NO, MO. In the group of patients, with positive urethral margins, the average preoperative PSA serum level was 37 ng/ml and the average tumor weight was 14 g. Postoperative pelvic radiation therapy (45 grays) was performed in 5 of these patients. The mean follow-up is 36 months (12-68). PSA serum level is undetectable in 4 cases, and 0.4 ng/ml in 1 case. Urinary PSA level is undetectable in 5 out of 6 cases.

Peroperative analysis of surgical margins, and particularly urethral margins, during RP allows to a better staging and to perform any tumor excision complement if possible. Surgical margins analysis when performed during surgery should help for the choice of the most adapted surgical procedure. In our experience, nerve-sparing RP are performed only when surgical margins are negative on frozen sections.