Prognostic significance of gleason grade at the surgical margin following radical prostatectomy.

Abstract

Introduction & Objectives: The prognostic significance of a positive surgical margin (PSM) after radical prostatectomy (RP) is well-established. However, the clinical impact of a PSM containing only low-grade Gleason 3 cancer is less certain - its virtually non-existent metastatic potential has ignited debate over whether it should be classified as 'cancer' at all. Therefore, we aim to evaluate the risk of biochemical recurrence (BCR) in patients with an isolated Gleason 3 PSM compared to those with negative surgical margins (NSM). Method(s): We retrospectively analysed a cohort of 135 patients who underwent RP between 2019 and 2022. BCR free survival was compared across margin status groups (NSM, Gleason 3, 4, or 5 at margin) using Kaplan-Meier analysis and multivariable Cox regression. Result(s): Overall, 129 patients were included. Table 1 on Kaplan-Meier analysis, Fig. 1 there was no statistically significant difference in BCR-free survival between the NSM group and the Gleason 3 at the margin group (P = 0.15). The rate of salvage or adjuvant radiotherapy is 30.8% vs 19.3% for Gleason 3 at PSM and NSM respectively. In contrast, Gleason 4 or 5 at the margin was associated with significantly worse BCR-free survival (P < 0.0001). In multivariable analysis, independent predictors of BCR were advanced pathological stages (pT3-4: HR 2.21, P = 0.03), Gleason 4 at the margin (HR 3.04, P = 0.005), and Gleason 5 at the margin (HR 4.54, P = 0.02). Conclusion(s): An isolated Gleason 3 PSM does not significantly increase BCR risk compared to NSM following RP. The grade of the cancer at the margin is a critical prognostic factor, with higher-grade disease conferring a significantly greater risk of BCR. These findings suggest that patients with an isolated Gleason 3 positive margin may be candidates for observation rather than aggressive adjuvant therapy.