Positive surgical margins and local recurrence after simple enucleation and standard partial nephrectomy for malignant renal tumors: systematic review of the literature and meta-analysis of prevalence.

BACKGROUND: The definition of the safest width of healthy renal margin to achieve oncological efficacy and therefore of the safest resection technique (RT) during partial nephrectomy (PN) continues to be widely debated. The aim of this study is to evaluate the prevalence of positive surgical margins (PSM), loco-regional recurrence (LRR) and renal recurrence (RER) rates after simple enucleation (SE) and standard partial nephrectomy (SPN) for malignant renal tumors in studies with a minimum follow-up of 2 years. EVIDENCE ACQUISITION: A systematic review of the English-language literature was performed through August 2016 using the Medline, Web of Science and Embase databases according to the PRISMA criteria. A systematic review and meta-analysis was performed in those studies that defined the exact anatomical location of recurrence after PN. EVIDENCE SYNTHESIS: Overall, 33 studies involving 11282 patients were selected for quantitative analysis. At a median follow up of 43 (SE) and 52 (SPN) months, the pooled estimates of the prevalence of PSMs, LRR and RER were 2.7% (95% CI: 1.5-4.6%, p<0.001) and0.4% (95% CI: 0.1-2.2%, p=0.018), 2.0% (95% CI: 1.4-2.8%, p<0.001) and 0.9% (95% CI: 0.5-1,7%p=0.04), 1.5% (95% CI: 0.9-2.3%, p=0.001) and 0.9% (95% CI: 0.5-1,7%, p=0.40) in patients undergoing SPN and SE, respectively. CONCLUSIONS: Our systematic analysis and meta-analysis demonstrates that SE is noninferior to SPN regarding PSM, LRR and RER rates in patients undergoing PN for malignant renal tumors. Further studies using standardized reporting tools are needed to evaluate the role of resection techniques for oncologic outcomes after PN.