Predictors of positive surgical margins after robot-assisted radical prostatectomy. A prospective cohort study and a systematic review with meta-analysis.

INTRODUCTION

Positive surgical margins (PSMs) after robot-assisted laparoscopic radical prostatectomy (RALRP) are linked to increased biochemical recurrence risk, but predictors remain inconsistent. This study aimed to identify predictors of PSM through a prospective cohort analysis and a systematic review with meta-analysis.

MATERIAL AND

METHODS

We analyzed 100 consecutive patients undergoing RALRP at a tertiary centre (2016-2018). Logistic regression assessed associations between clinical, pathological, and surgical variables and PSM. Cox regression evaluated the impact of PSM on biochemical recurrence. In parallel, a meta-analysis of studies reporting regression-based predictors of PSM after RALRP was conducted. Random-effects models pooled adjusted and unadjusted odds ratios.

RESULTS

In the cohort, 22% of patients had PSM, most frequently at the apex. Lower prostate weight was the only independent predictor of PSM (OR = 0.964 per gram; 95% CI: 0.95-0.98). PSM independently predicted biochemical recurrence (HR = 5.29; 95% CI: 1.38-20.19). The meta-analysis of 13 studies confirmed significant associations between PSM and higher pathological T stage (aOR = 5.58; 95% CI: 1.95-9.20), higher prostate-specific antigen level (aOR = 1.05 per ng/ml; 95% CI: 1.01-1.09), and higher pathological Gleason score. Larger prostate weight and volume were protective. Associations with biopsy Gleason score, body mass index, nerve-sparing status, and age were inconsistent.

CONCLUSIONS

Tumour aggressiveness, reflected by pathological stage, capsular invasion, and Gleason score, is the strongest determinant of PSM after RALRP, while larger prostate weight is protective. Integrating cohort and meta-analytic findings provides a comprehensive synthesis of factors associated with surgical margin status that may inform future risk stratification and surgical planning.