title: Primary nephrectomy and intraoperative tumor spill: report from the Children's Oncology Group (COG) renal tumors committee.
abstract: OBJECTIVE
  Initial Children's Oncology Group (COG) management for Wilms' tumor (WT) consists of primary nephroureterectomy with lymph node sampling. While this provides accurate staging to define further treatment, it may result in intraoperative spill (IOS), which is associated with higher recurrence rates and therefore requires more intensive therapy. The purpose of this study is to determine current rates and identify factors which may predispose a patient to IOS.
  
  
  METHODS
  The study population was drawn from the AREN03B2 renal tumor banking and classification study of the Children's Oncology Group. All children with a first time occurrence of a renal mass were eligible for the study. At the time of enrollment and prior to risk stratification, the institution is required to submit operative notes, pathology specimens, a chest computed tomography scan (CT), and a contrast-enhanced CT or magnetic resonance imaging (MRI) of the abdomen and pelvis for central imaging review. These data are then used to determine an initial risk classification and therapeutic protocol eligibility. Patients who had a unilateral nephroureterectomy for favorable histology WT underwent further review to assure data accuracy and to clarify details regarding the spill. Analyses were performed using chi square and logistic regression. Odd ratios (OR) are shown with 95% confidence intervals.
  
  
  RESULTS
  There were 1,131 primary nephrectomies for unilateral WT with an IOS rate of 9.7% with an additional 1.8% having possible tumor spill during renal vein or IVC tumor thrombectomy. IOS correlated with diameter (>12 cm, p<0.0001) and laterality (right, p=0.0414). Simple logistic regression indicated that IOS increased 2.7% [p=0.0240, OR 1.027 (1.004, 1.052)] with each 1 cm increase in diameter (3 - 21 cm) and 4.7% [p=0.0147 OR 1.047 (1.009, 1.086)] with each 100 g increase in weight (80 - 1800 g). Multiple logistic regression indicated that laterality [right p=0.048, OR 1.46 (1.004, 2.110)] and weight (p=0.03, OR 1.039 (1.003, 1.075) were predictive of IOS when diameter was included as a continuous variable. Diameter as a binary variable was highly prognostic of IOS (p=0.0002), while laterality and weight were not significant.
  
  
  CONCLUSIONS
  Intraoperative tumor spill occurs in about one out of every ten cases of primary nephroureterectomies for WT. Right-sided and larger tumors are at higher risk of IOS.
authors: Seattle Children's Hospital and University of Washington, Seattle, WA 98105, USA. Kenneth.gow@seattlechildrens.org
authors: Kenneth W
authors: KW
authors: Gow
authors: Douglas C
authors: DC
authors: Barnhart
authors: Thomas E
authors: TE
authors: Hamilton
authors: Jessica J
authors: JJ
authors: Kandel
authors: Mike K S
authors: MK
authors: Chen
authors: Fernando A
authors: FA
authors: Ferrer
authors: Mitchell R
authors: MR
authors: Price
authors: Elizabeth A
authors: EA
authors: Mullen
authors: James I
authors: JI
authors: Geller
authors: Eric J
authors: EJ
authors: Gratias
authors: Nancy
authors: N
authors: Rosen
authors: Geetika
authors: G
authors: Khanna
authors: Arlene
authors: A
authors: Naranjo
authors: Michael L
authors: ML
authors: Ritchey
authors: Paul E
authors: PE
authors: Grundy
authors: Jeffrey S
authors: JS
authors: Dome
authors: Peter F
authors: PF
authors: Ehrlich
mesh_terms: D016009:Chi-Square Distribution; D002648:Child; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology / Q000209:etiology*; D007680:Kidney Neoplasms / Q000601:surgery*; D016015:Logistic Models; D009366:Neoplasm Seeding; D009392:Nephrectomy / Q000009:adverse effects*; D016017:Odds Ratio; D012307:Risk Factors; D009396:Wilms Tumor / Q000601:surgery*