title: A proposal for an international retinoblastoma staging system.
abstract: BACKGROUND
  Although intra-retinal tumor has long been staged presurgically according to the Reese-Ellsworth (R-E) system, retinoblastoma differs from other pediatric neoplasms in never having had a widely accepted classification system that encompasses the entire spectrum of the disease. Comparisons among studies that consider disease extension, risk factors for extra-ocular relapse, and response to therapy require a universally accepted staging system for extra-ocular disease.
  
  
  METHODS
  A committee of retinoblastoma experts from large centers worldwide has developed a consensus classification that can encompass all retinoblastoma cases and is presented herein. Patients are classified according to extent of disease and the presence of overt extra-ocular extension. In addition, a proposal for substaging considering histopathological features of enucleated specimens is presented to further discriminate between Stage I and II patients.
  
  
  RESULTS
  The following is a summary of the classification system developed-Stage 0: Patients treated conservatively (subject to presurgical ophthalmologic classifications); Stage I: Eye enucleated, completely resected histologically; Stage II: Eye enucleated, microscopic residual tumor; Stage III: Regional extension [(a) overt orbital disease, (b) preauricular or cervical lymph node extension]; Stage IV: Metastatic disease [(a) hematogenous metastasis: (1) single lesion, (2) multiple lesions; (b) CNS extension: (1) prechiasmatic lesion, (2) CNS mass, (3) leptomeningeal disease]. A proposal is also presented for substaging of enucleated Stages I and II eyes.
  
  
  CONCLUSIONS
  The proposed staging system is the product of an international effort to adopt a uniform staging system for patients with retinoblastoma to cover the whole spectrum of the disease.
authors.affiliation: Department of Hematology-Oncology, Hospital JP Garrahan, Buenos Aires, Argentina. gchantada@garraha.gov.ar
authors.forename: Guillermo
authors.initials: G
authors.lastname: Chantada
authors.forename: François
authors.initials: F
authors.lastname: Doz
authors.forename: Celia B G
authors.initials: CB
authors.lastname: Antoneli
authors.forename: Richard
authors.initials: R
authors.lastname: Grundy
authors.forename: F F
authors.initials: FF
authors.lastname: Clare Stannard
authors.forename: Ira J
authors.initials: IJ
authors.lastname: Dunkel
authors.forename: Eric
authors.initials: E
authors.lastname: Grabowski
authors.forename: Carlos
authors.initials: C
authors.lastname: Leal-Leal
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodríguez-Galindo
authors.forename: Enrique
authors.initials: E
authors.lastname: Schvartzman
authors.forename: Maja Beck
authors.initials: MB
authors.lastname: Popovic
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kremens
authors.forename: Anna T
authors.initials: AT
authors.lastname: Meadows
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Zucker
mesh_terms: D006801:Humans; D009367:Neoplasm Staging / Q000592:standards*; D019572:Retinal Neoplasms / Q000145:classification* / Q000175:diagnosis* / Q000473:pathology; D012175:Retinoblastoma / Q000145:classification* / Q000175:diagnosis* / Q000473:pathology