Positive Surgical Margins After Partial Nephrectomy: A Systematic Review and Meta-Analysis of Comparative Studies

Abstract

Objective: We performed an update of previous reviews of the literature to provide an overview on incidence, predictive factors, management and prognosis of positive surgical margins (PSMs) after partial nephrectomy (PN) including recent surgical series and studies comparing different approaches and techniques. Material and methods: A literature search was performed from January 2013 to January 2018 using the Medline database. The search strategy included a free-text protocol using the term “nephron-sparing surgery” OR “partial nephrectomy” AND “positive surgical margins” across the title and abstract fields of the records. From each selected study, we extracted the following data: number of analyzed patients, study design, approach and surgical technique used, PSMs rate, pathological features, type of PSMs treatment, mean (median) follow-up duration and final patient status. Meta-analysis was conducted using Review Manager software v. 5.2 (Cochrane Collaboration, Oxford, UK). Results: We selected a total of 36 (48%) studies. All studies were retrospective and the best statistical method used for comparison was the matched-pair analysis (level 4). Overall, 45,786 patients treated with PN were included in the selected studies. PSMs were reported in a total of 3,093 (6.7%) patients. The mean estimated PSMs rate was 7%, 5% and 4.3% in patients who underwent robot-assisted PN (RAPN), laparoscopic PN (LPN) and open PN (OPN), respectively. Comparative studies showed a significant advantage in favor of OPN compared with minimally invasive approach, while RAPN showed more favourable PSMs risk compared with LPN (odds ratio 3.02, 95% confidence intervals 2.05–4.45). No differences were detected stratifying data according to other surgical or tumor-related factors. Tumor size, nuclear grading and pT3a stage represent the most important predictors of PSMs. In 6,809 patients, follow-up data were available. Only 101 (1.4%) local recurrences and 88 (1.3%) distant recurrences were observed both in PSMs and negative surgical margins subgroups. PSMs were associated with a significant increased risk of local recurrence with a significant impact on local recurrence-free survival and metastasis-free survival. However, a significant impact on cancer-specific and overall survival could not be demonstrated. Conclusions: Studies published in the last 5 years confirmed that PSMs after PN are a rare condition. Although PSMs increase the risk of local and distant recurrence, their influence on cancer-specific and overall survival seems to be limited. Close surveillance should be strongly recommended as initial treatment of patients with PSMs after PN.