title: The prognostic significance of blastemal predominant histology in initially resected Wilms' tumors: a report from the Study Group for Pediatric Solid Tumors in the Kyushu Area, Japan.
abstract: OBJECTIVE
  The strategy used to treat pediatric renal tumors in Japan is based on the Japanese Wilms' Tumor Study (JWiTS) protocol, which was based on the National Wilms' Tumor Study (NWTS)-5 regimen. The regimen is characterized by an initial radical operation, followed by adjuvant chemotherapy and radiotherapy. Concerning the histological classification, a new classification based on the International Society of Pediatric Oncology (SIOP) classification was used beginning in 2008. The main points of revision are that the "blastemal predominant type" was classified as an independent category in the Wilms' tumor subtypes. The purpose of this study was to analyze the biological characteristics from the standpoint of the newly established histological classification.
  
  
  METHODS
  From 1971 to 2005, 174 cases of Wilms' tumors treated with an initial operation followed by adjuvant therapy were re-evaluated by the new histological classification. Histologically, all these materials showed no secondary changes associated with adjuvant therapy.
  
  
  RESULTS
  According to the new classification, Wilms' tumors were classified into four subtypes, including the mixed type (n=112), epithelial type (n=17), mesenchymal type (n=15), and blastemal predominant type (n=26). The 5 year overall survival rates were as follows; mixed type (90.1%), epithelial type (100%), mesenchymal type (93.3%), and blastemal predominant type (65.4%).
  
  
  CONCLUSIONS
  The patients with blastemal predominant tumors demonstrated a significantly worse prognosis compared with those of other subtypes. The treatment strategy of blastemal predominant category should be distinguished from the other favorable subtypes.
authors.affiliation: The Committee for Pediatric Solid Malignant Tumors in Kyushu area, Japan. kinoppy@pedsurg.med.kyushu-u.ac.jp
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: Aiko
authors.initials: A
authors.lastname: Suminoe
authors.forename: Hiroko
authors.initials: H
authors.lastname: Inada
authors.forename: Minoru
authors.initials: M
authors.lastname: Yagi
authors.forename: Fumio
authors.initials: F
authors.lastname: Yanai
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Zaizen
authors.forename: Masanori
authors.initials: M
authors.lastname: Nishi
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Inomata
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kawakami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsufuji
authors.forename: Souichi
authors.initials: S
authors.lastname: Suenobu
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Handa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kohashi
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.forename: Toshiro
authors.initials: T
authors.lastname: Hara
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Taguchi
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols; D001707:Biopsy, Needle; D059186:Chemoradiotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003131:Combined Modality Therapy / Q000379:methods; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007564:Japan; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome; D009396:Wilms Tumor / Q000401:mortality / Q000473:pathology* / Q000628:therapy*