Is cytoreductive nephrectomy necessary for metastatic renal cell carcinoma: a systematic review and meta-analysis

Objective: The goal of this study was to explore the necessity of cytoreductive nephrectomy for metastatic renal cell carcinoma. Methods: A systematic search was conducted using PubMed, Cochrane Library, Web of Science, and EMBASE through June 20, 2018 according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines to identify studies reporting on cytoreductive nephrectomy for metastatic renal cell carcinoma. Results: Of a total of 669 studies, 19 were considered for evidence synthesis. A total of 59,915 patients were included, with a median of 3,153 patients per study. Of these, 24,210 patients received cytoreductive nephrectomy and 35705 patients received other therapy. Patients treated with cytoreductive nephrectomy obtained a reduced risk of death comparing with those treated with other therapies (HR=0.50; 95% CI, 0.45-0.56; P<.001; I-2=91.9%). In subgroup analysis, a similar outcome was obtained for targeted therapy as cytoreductive nephrectomy reduced 48% risk of mortality (HR=0.52; 95% CI, 0.46-0.59; P<.001). For cytokine therapy, cytoreductive nephrectomy also contributed to a positive prognosis but not statistically significant (HR=0.67; 95% CI, 0.54-0.82; P=0.423). Conclusion: Targeted therapy or immunotherapy alone was inferior to combine with cytoreductive nephrectomy for metastatic renal-cell carcinoma patients. Cytoreductive nephrectomy combined with targeted therapy was optimal treatment for metastatic renal-cell carcinoma patients.