Objective: To prospectively examine the effects of the margin status after radical prostatectomy (RP), the location, and the number of positive surgical margins (PSMs) on biochemical and clinical outcome, as even if there seems to be little debate that there is a higher risk of both local and distant recurrence of prostate cancer in the face of a PSM the significance of a PSM after RP is only followed for biochemical progression in most studies.
Patients and methods: From our prospective database, 406 consecutive well-described patients without neoadjuvant and 'direct postoperative' adjuvant therapy who underwent RP were included. The median age was 64.7 years, the median preoperative PSA level was 7.9 ng/mL, and the median follow-up was 5.2 years. We analysed pathological tumour stage, grading, number and location of PSMs, PSA-free survival, local recurrence-free survival, metastasis-free survival, prostate cancer-specific and, overall survival prospectively.
Results: The overall rate of PSMs was 17.2%. The number was higher in higher stage (P < 0.001) and higher grade tumours (P = 0.041). For a PSM the PSA recurrence rate was 64.3%, the local recurrence rate was 18.6%, the development of distant metastasis was 15.7% and therefore much higher than in patients with negative margins (20.5%, 2.7%, and 1.5%). A PSM was an adverse predictor for PSA-free survival (P < 0.001), local recurrence-free survival (P = 0.002), and development of metastasis (P = 0.003) on multivariate analysis. The number and location of PSMs was of no additional prognostic value.
Conclusions: A PSM increases the risk of biochemical and clinical e.g. local, disease progression after RP. The number and location of PSMs is of minor importance. Although only approximately 20% of patients with a PSM will develop local recurrence, surgeons should continue to strive to reduce the rate of PSMs to improve cancer control.