Length of positive surgical margins after radical prostatectomy: Does size matter? – A systematic review and meta-analysis

Objectives: The prognostic capacity of positive surgical margins (PSM) for biochemical recurrence (BCR) is unclear, with inconsistent findings across published studies. We aimed to systematically review and perform a meta-analysis exploring the impact of Positive surgical margin length on biochemical recurrence in men after radical prostatectomy. 

Methods: A search was conducted using the MEDLINE, Scopus, Embase and Cochrane databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. The quality of the studies was assessed using the Newcastle-Ottawa scale, and the protocol was registered in advance (PROSPERO: CRD42020195908). This meta-analysis included 16 studies with BCR as the primary outcome measure.

Results: Studies used various dichotomised thresholds for PSM length. A subgroup meta-analysis was performed using the reported multivariable hazard ratio (Continuous, 3, and 1 mm PSM length). PSM length (continuous) was independently associated with an increased risk of BCR (7 studies, HR 1.04 (CI 1.02–1.05), I² = 8% p < 0.05). PSM length greater than 3 mm conferred a higher risk of BCR compared to less than 3 mm (4 studies, HR 1.99 (1.54–2.58) I² = 0%, p < 0.05). There was also an increased risk of BCR associated with PSM length of less than 1 mm compared to negative surgical margins (3 studies, HR 1.46 (1.05–2.04), I² = 0%, P = 0.02). 

Conclusion: PSM length is independently prognostic for BCR after radical prostatectomy. Further long-term studies are needed to estimate the impact on systemic progression.