Positive Surgical Margins After Radical Retropubic Prostatectomy: The Influence of Site and Number on Progression

Abstract

We assessed the effect of location and number of positive margins on biochemical progression in patients after radical retropubic prostatectomy for prostate cancer. The incidence, location and number of positive surgical margins as well as recurrence and time to recurrence were evaluated in a consecutive series of 734 men who underwent radical retropubic prostatectomy for localized prostate cancer from 1992 through February 1999. Surgical margins were positive in 210 patients (29%), of whom 157 (75%) and 53 (25%) had 1 and more than 1 positive margin, respectively. Of the patients 53 (25%) with tumor at any inked margin had biochemical recurrence. We identified no significant association of a particular location with biochemical recurrence. Bladder neck location did not carry an increased risk of recurrence (hazard ratio 1.23, 95% confidence interval 0.54 to 2.80). However, these findings were made in a limited number of cases with positive bladder neck margins. Patients with more than 1 positive surgical margin were at increased risk for recurrence compared with those with a single positive surgical margin (hazard ratio 2.19, 95% confidence interval 1.11 to 4.32). In addition, prostate specific antigen greater than 20 ng./ml. and seminal vesicle invasion were significant predictors of progression. In patients with localized prostate cancer and positive surgical margins biochemical progression is not dictated by the specific location of a positive margin. However, multiple positive margins are associated with a significantly increased risk of biochemical recurrence. Longer followup and larger sample size are necessary to confirm these findings.