Length of site-specific positive surgical margins as a risk factor for biochemical recurrence following radical prostatectomy.

OBJECTIVES: Positive surgical margins (PSM) have been associated with biochemical recurrence (BCR) after radical prostatectomy, but the significance of PSM length and location are debated. We assessed the impact of PSM lengths at specific locations for BCR in an open radical prostatectomy series.
METHODS: Detailed clinical and pathological data were collected from 117 post-prostatectomy patients with PSM from 1984 to 2004 at our institution. PSM locations were classified as apex, mid-gland, base, bladder neck, and anterior fibromuscular region with lengths measured at each site. Aggregate PSM length was obtained by summing lengths of all PSM areas in contact with the inked surface. BCR was defined as serum prostate specific antigen level 0.2 ng/mL or greater. Cox proportional hazards regression analyses of PSM lengths were conducted either as a continuous or categorical variable relative to location as a predictor of BCR.
RESULTS: Multivariate analyses demonstrated that as a continuous variable, PSM length at the anterior fibromuscular region (Hazard ratio [HR] = 1.17; P = 0.027) and bladder neck (HR = 1.29; P = 0.046) were significant predictors for BCR. As a categorical variable, PSM length ≥ 2 mm at the anterior fibromuscular area was significant for BCR (HR = 3.02; P = 0.036). Increasing Gleason grade and positive lymph node status were also found to be significant independent predictors for BCR.
CONCLUSION: PSM length at the anterior fibromuscular region (continuous and categorical) and the bladder neck (continuous) was significantly associated with BCR. Site-specific PSM length, along with Gleason grade and lymph node status, can be predictive of BCR and assist in risk stratification of patients with PSM following radical prostatectomy.