Aims: To evaluate the prognostic role of the length of a positive surgical margin (+SM) for biochemical recurrence (BCR) after radical prostatectomy (RP) for prostatic cancer.
Methods and results: Consecutive RP specimens (n = 267) with +SM were analysed. All RP specimens were sectioned at 4-mm intervals and completely embedded. Data were analysed using Kaplan-Meier survival analysis and proportional hazards models. In 267 patients the length of +SM ranged from 0.4 to 174.5 mm (median 11.2 mm) and correlated with preoperative prostate specific antigen (PSA) (P < 0.001), pathological stage (P < 0.001), tumour volume (P = 0.001), number of +SM (P < 0.001), Gleason grade at +SM (P < 0.001) and Gleason score (P = 0.015). Patients with detectable postoperative PSA levels (n = 34) or adjuvant therapy (n = 59) were excluded from BCR analysis. In the remaining 174 patients the 5-year risk of BCR was 29%; in patients with +SM <or=10 mm and >10 mm this was 21% and 39%, respectively. On multivariable analysis BCR was associated with an increasing length of +SM (<or=10 mm versus >10 mm; hazard ratio 2.15; 95% confidence interval 1.12, 4.15; P = 0.022).
Conclusions: The length of +SM is an independent prognostic factor for BCR in patients with undetectable PSA after RP.