title: Nephron-sparing surgery for Wilms tumor: A systematic review.
abstract: BACKGROUND
  Radical nephrectomy (RN, or total nephrectomy) is the current gold-standard surgical treatment for children with Wilms tumors (WT). However, nephron-sparing surgery (NSS, or partial nephrectomy) has recently been gaining increasing attention. The objective of this systematic review is to compare the effectiveness of NSS as compared with RN for the treatment of children with WT.
  
  
  METHODS
  We searched the Cochrane Controlled Trials Register, clinicaltrials.gov, MEDLINE, EMBASE, Google Scholar, and recently presented meeting abstracts for reports in English. The bibliographies of included studies were then hand-searched for any missed articles. The protocol was prospectively registered. Manuscripts were assessed and data abstracted in duplicate with differences resolved by the senior author. Owing to high heterogeneity among the final included studies, only a qualitative systematic review was performed; no formal meta-analysis was undertaken.
  
  
  RESULTS
  We identified 694 articles, 118 of which were selected for full-text review and 66 of which were included in the final analysis. Most studies were single- or multi-institution retrospective case series (60, 91%), with a small number of prospective cohort studies (6, 9%) and 1 administrative database analysis. Most studies were from Europe (27, 41%) or North America (21, 32%). Nearly half (32, 48%) of studies those were included were dated from 2010 or later. In total, data on 4,002 patients were included, of whom 1,040 (26%) underwent NSS and 2,962 (74%) underwent NSS. Reported rupture rates were similar between RN and NSS (13% vs. 7%), as were recurrence rates (12% vs. 11%) and survival rates (85% vs. 88%). However, these comparisons are limited by inherent biases in the design and reporting of most included studies.
  
  
  CONCLUSIONS
  Most contemporary studies reporting the use of NSS in children with WT report similar long-term outcomes to RN. However, most existing studies are limited by their small numbers, inconsistent reporting, and methodological biases. There are significant opportunities for future research on the use of NSS in children with WT, including issues related to surgical quality, optimal technique, timing and duration of chemotherapy, and variation in the use of NSS among centers.
authors.affiliation: Duke University School of Medicine, Durham, NC.
authors.forename: Rand N Wilcox
authors.initials: RN
authors.lastname: Vanden Berg
authors.affiliation: North Carolina State University, Raleigh, NC.
authors.forename: Emily N
authors.initials: EN
authors.lastname: Bierman
authors.affiliation: Duke University medical Library, Durham, NC.
authors.forename: Megan Van
authors.initials: MV
authors.lastname: Noord
authors.affiliation: Duke University School of Medicine, Durham, NC; Division of Pediatric Surgery, Department of Surgery, Duke University Medical Center, Durham, NC.
authors.forename: Henry E
authors.initials: HE
authors.lastname: Rice
authors.affiliation: Duke University School of Medicine, Durham, NC; Division of Urologic Surgery, Department of Surgery, Duke University Medical Center, Durham, NC. Electronic address: Jonathan.Routh@duke.edu.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Routh
mesh_terms: D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D009399:Nephrons / Q000601:surgery*; D059351:Organ Sparing Treatments; D009396:Wilms Tumor / Q000601:surgery*
keywords: Nephron-sparing surgery; Partial nephrectomy; Pediatric; Radical nephrectomy; Renal tumor; Wilms tumor