Outcome of patients with Stage II/favorable histology Wilms tumor with and without local tumor spill: a report from the National Wilms Tumor Study Group

Pediatr Blood Cancer. 2014 Jan;61(1):134-9. doi: 10.1002/pbc.24658. Epub 2013 Aug 23.


Background: Intra-operative tumor spill increases the risk of local recurrence of Wilms tumor, and adversely impacts relapse-free (RFS) and overall survival (OS) rates.

Methods: Surgical checklists, operative notes, institutional pathology reports, central pathology review and flow sheets of 602 patients registered between August 1986 and September 1994 on National Wilms Tumor Study-4 as randomized, followed or switched and coded as Final Stage II, favorable histology (FH) were reviewed. RFS and OS were estimated using the Kaplan-Meier method. Hazard ratios (HRs) were estimated using the Cox model and tested for statistical significance by the log-rank test.

Results: Four hundred ninety-nine patients were found after review to have Stage II, FH Wilms tumor. The 8-year RFS percentages were 85.0% (95% confidence interval (CI): 81.1%, 88.1%) for those with no spill compared to 75.7% (65.8%, 83.2%) for those with spill. The 8-year OS percentages were 95.6% (93.1%, 97.3%) for those with no spill compared to 90.3% (82.2%, 94.9%) for those with spill. The HR for relapse among those with spill was 1.55 ((95%CI: 0.97,2.51), P = 0.067) and the HR for death was 1.94 ((0.92,4.09), P = 0.077).

Conclusions: RFS and OS were lower for patients who had intra-operative tumor spill. The majority of NWTS Stage II, FH patients with intra-operative tumor spill have an overall excellent outcome when treated with two drug chemotherapy (vincristine and actinomycin D) and no abdominal irradiation.

Keywords: Wilms tumor; actinomycin D; doxorubicin; oncology; radiation therapy; vincristine.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Combined Modality Therapy
  • Dactinomycin / administration & dosage
  • Disease-Free Survival
  • Humans
  • Kaplan-Meier Estimate
  • Kidney Neoplasms / mortality
  • Kidney Neoplasms / pathology
  • Kidney Neoplasms / surgery*
  • Neoplasm Seeding*
  • Neoplasm Staging
  • Nephrectomy / adverse effects*
  • Radiotherapy
  • Treatment Outcome
  • Vincristine / administration & dosage
  • Wilms Tumor / mortality
  • Wilms Tumor / pathology
  • Wilms Tumor / surgery*


  • Dactinomycin
  • Vincristine