Effect of Positive Surgical Margins in Patients Who Undergo a Partial Nephrectomy Regarding Recurrence, Overall Survival, Recurrence/Progression-Free Survival, and Metastasis-Free Survival. A Systematic Review and Meta-Analysis.

BACKGROUND: To determine the effect of positive surgical margins in patients who undergo a partial nephrectomy regarding recurrence, overall survival, disease-free survival, recurrence and progression-free survival, and metastasis-free survival. METHODS: We performed a systematic review accomplishing with Cochrane recommendations. We searched in Medline, Embase, and central. We also looked for unpublished literature. There was no language or setting restrictions. We performed a random-effects meta-analysis for all outcomes. RESULTS: We included 44 studies for qualitative and quantitative analysis. We found that positive margins increase the risk of local recurrence (RR 4.14 95%CI 2.75-6.24), recurrence (RR 4.8 95%CI 3.38-6.62), mortality (RR 1.83 95%CI 1.08-3.1), metastasis (RR 8.1 95%CI 3.88-16.92), and improved the recurrence/progression-free survival (HR 2.9 95%CI 1.88-4.49) and metastasis-free survival (HR 2.91 95%CI 1.25-6.79) with moderate, moderate, very low, very low, and high certainty of the evidence, respectively. We found no change in overall survival (HR 1.48 95%CI 0.98-2.22) with very low certainty of evidence. CONCLUSIONS: A positive margin is an independent predictor of local recurrence, recurrence, mortality, metastasis, with no effect on overall survival. Therefore, a tailored intense and prolonged follow-up is mandatory.