Are positive surgical margins in radical prostatectomy specimens an independent prognostic marker?

A positive surgical margin (PSM) is considered an adverse prognostic indicator in patients undergoing radical prostatectomy (RP). However, there are discrepancies among studies concerning the effect of PSM on prognosis. In addition, the significance of PSM location and extent is uncertain. The aim of this study was to examine the impact of surgical margin status on serum prostate-specific antigen (sPSA) relapse in men consecutively receiving RP in a non-screened population.

In total, 219 prostatectomy specimens were examined microscopically. The mean follow-up time was 62 months (range 6-121 months). Tumour grade (Gleason score), pathological tumour stage and tumour involvement of the surgical margins were recorded. The 71 specimens with one or more PSM were re-examined with regard to location, number of locations and total linear extent of PSM. Kaplan-Meier plots and Cox proportional hazards regression were used in the univariate analyses. Multivariate analyses controlling for the known preoperative sPSA, pathological stage and Gleason score were also performed, using Cox proportional hazards regression.

In the univariate analyses, PSM without regard to location, PSM at the anterior prostate or at the apex, PSM at three or more locations and linear extent of PSM > or =6mm were associated with a statistically significant higher hazard ratio of PSA relapse. However, none of these variables remained statistically significant when controlling for the known risk factors.

In this non-screened prostate cancer population PSM status (linear extent, location and number of locations) had an impact on postoperative sPSA recurrence. In multivariate analyses PSM showed a strong trend (p approximately 0.06) towards having an independent statistically significant negative influence on the risk of PSA relapse following RP.