Prognostic implications of positive margins in radical prostatectomy specimens

Abstract

To evaluate the histopathologic implication of positive margins of prostatectomy specimens in the biochemical recurrence. Matherial and methods: The study group consisted of 290 patients with clinically localized prostate cancer who were treated by radical retropubic prostatectomy. Patients with neoadjuvant hormonal therapy and positive lymph nodes were excluded. The mean age at the time of surgery was 63 years (range 47-73); 166 (57.2%) patients were T1c and 124 (42.8%) T2; the average time of folow-up was of 4 years (range 1-12). Positive surgical margins were defined as the presence of cancer cells at the surface inked of prostatectomy specimens. They were classified as: Margin for capsular incision (without extraprostatic extension evidence)/ margin for extraprostatic extension, margin with smooth rounded surface/margin with irregular surface, margin ≤4 mm/margin >4 mm, unifocal margin/multifocal margin. We define biochemical recurrence if the PSA exceeds 0.20 ng/ml in two consecutive determinations. Results: The overall rate of positive margins was 65/290 (22.4%). The 5-year survival free of biochemical recurrence was as follows: Negative margins 71% vs positive margins 44% (p<0.001): positive margins for capsular incision 84% vs positive margins for extraprostatic extension 33% (p<0.01): positive margins with smooth rounded surface 58% vs positive margins with irregular surface 26% (p<0.01); positive margins ≤4 mm 57% vs positive margins >4 mm 32% (p<0.05); unifocal margins 53% vs multifocal margins 0% (p<0.01). The multivariate analysis revealed that preoperative PSA, Gleason score and pathological classification were the best predictors of biochemical recurrence. Conclusions: Two groups are established of positive margin. The first group with high probability of biochemical recurrence: margin for extraprostatic. The second group with less probability of biochemical recurrence: margin for capsular incision, margin with smooth rounded surface, margin ≤4 mm and unifocal margin.