Positive surgical margins after radical retropubic prostatectomy: The influence of site and number on progression

Purpose: We assessed the effect of location and number of positive margins on biochemical progression in patients after radical retropubic prostatectomy for prostate cancer. Materials and Methods: 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. Results: 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. Conclusions: 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.