Effect of partial nephrectomy with positive margin on recurrence and metastasis in patients with renal cancer: a Meta-analysis

Objective Systematic assessment of the effect of positive margin on recurrence and metastasis in patients with renal cell carcinoma who underwent partial nephrectomy. Methods The literature were searched on the rate of recurrence and metastasis in patients with positive margin and partial nephrectomy published in PubMed, Embase, Cochrane, China Biomedical Literature Database, China Knowledge Network, VIP Chinese Science and Technology Journal Database, and Wanfang Chinese Database up to December 2018. The quality of the literature included in this study was evaluated by two reviewers, and a meta-analysis was performed on the literature that met the inclusion criteria using the Revman 5.0 statistical software provided by Cochrane Collaboration. Results A total of seven articles were included, six of which were case-control studies, and the other one was a cohort study. These seven articles consisted of 6 928 patients, including 407 positive margins and 6 521 negative margins. For recurrence and metastasis, 407 positive margins were composed of 25 recurrences and 21 distant metastases, while 6 521 negative margins consisted of 68 recurrence and 96 distant metastasis. The disease-free survival rate of patients with positive margins is lower than that with negative margins (OR=4.92, 95%CI 2.66-9.08, P<0.001). The results of subgroup analysis of patients with recurrence and metastasis based on positive margin exhibited that positive margin increased the risk of recurrence in patients undergoing partial nephrectomy (OR=5.05, 95%CI 2.06-12.37, P<0.001), as well as the risk of metastasis (OR=3.70, 95%CI 2.18-6.26, P<0.001). Since different studies consisted of patients with different tumor staging, a stratified analysis was conducted and the disease-free survival rate of patients with positive margins decreased compared with that of negative margins (OR=4.13, 95%CI 2.54-6.70, P<0.001), although there were differences in the staging of tumor patients included in different studies, which did not weaken the results. Conclusions Positive margins increase the risk of recurrence and metastasis in patients undergoing partial nephrectomy. Key words: Kidney neoplasms; Partial nephrectomy; Positive margin; Recurrence; Metastasis; Meta-analysis