The perks of combining extension and Gleason score of positive surgical margins after robot-assisted radical prostatectomy.

[BACKGROUND] The role of positive surgical margins' (PSM) features in terms of cancer control outcomes is unclear. We aimed to test the association between PSM extension combined to highest Gleason score (GS) at margin and PSA persistence, biochemical recurrence (BCR) and clinical recurrence (CR) in prostate cancer (PCa) patients undergone robot-assisted radical prostatectomy (RARP).

[MATERIALS AND METHODS] 2617 PCa patients treated with RARP at six European centers were stratified according to the PSM status and features, as follows): (a) negative SM; (b) focal PSM-GS 3; (c) extensive PSM-GS 3; (d) focal PSM-GS 4-5; (d) extensive PSM-GS 4-5. Multivariable logistic regression models addressed PSA persistence. Kaplan-Meier plots and multivariable Cox regression models addressed BCR and CR according to PSM status and features. Sensitivity analyses in patients with and without adverse pathological features were performed.

[RESULTS] Overall, 790 (30%) patients harbored PSM, 31% with GS 3 and 69% with GS 4-5, whereas 51% were focal and 49% were extensive. PSA persistence was independently predicted by "focal and extensive PSM-GS 4-5" combinations (odds ratios 1.57 and 2.17, respectively). BCR free survival at 36 months was 92 vs. 82% in respectively NSM and PSM patients. Only "extensive PSM-GS 4-5" combination was independently associated with BCR (hazard ratio [HR] 2.53). CR free survival at 36 months was 95 vs. 91% in respectively NSM and PSM patients. Only "extensive PSM-GS 4-5" combination was independently associated with CR (HR 1.45).

[CONCLUSIONS] PCa patients harboring "extensive PSM-GS 4-5" combination at final pathology have worse oncological outcomes compared to their NSM counterparts or PSM patients with less unfavorable PSM features. These findings may help to improve patients counselling, especially in case of additional treatments' decision making.