Positive surgical margins with radical prostatectomy: detailed pathological analysis and prognosis.

OBJECTIVES

To examine the extent and location of positive surgical margins and their influence on progression.

METHODS

Two hundred fifteen consecutive radical prostatectomy specimens, using 2 to 3-mm step-sections, were reviewed. Particular attention was paid to the location and extent of positive margins. Seventy-three patients (34%) with one or more positive margins were subjected to further detailed analysis. Progression was defined as a serum prostate-specific antigen level greater than 0.1 ng/mL and rising. The mean follow-up period was 23.2 months; median 24 months (range 3 to 40).

RESULTS

Margin-positive patients had a significantly higher biopsy tumor grape (P = 0.05) than did margin-negative patients. Capsular preforation was present in 75%, seminal vesicle invasion in 33%, and nodal metastases in 10% of margin-positive patients; in contrast, these tumor characteristics were present in 47%, 8%, and 1% of margin-negative patients, respectively. The extent of involvement of linked margins was focal in 22% and extensive in 66%. An equivocal margin identified as surgical incision into the specimen (due to hemostatic staples, surgical dissection, or retraction) was present in 12%. Seventy-one percent of patients had a positive margin at only one location. Of all 99 positive-margin locations, 40% were apical, 10% anterior, 8% bladder neck, 16% posterolateral, and 25% posterior. Thirty-four percent of margin-positive and 7% of the margin-negative patients demonstrated biochemical progression. Of the 36 patients with a positive margin as their only major risk factor for progression (seminal vesicle and lymph node negative, Gleason score less than 8), 25% have progressed. Progression occurred in 2 of 9 patients with an equivocal positive margin, and 5 of 16 with a single focal-positive margin. A multivariate analysis of margin-positive patients identified tumor volume and grade as the most significant predictors, with the location and extent of the positive margin not significant.

CONCLUSIONS

Although more frequent at the prostatic apex, tumor at the inked margin at any location is a risk factor for postoperative biochemical progression.