title: Relapse of unilateral favorable histology Wilms' tumor: significant clinicopathological factors.
abstract: OBJECTIVE
  To evaluate the clinicopathological features that indicate relapse and suggest a new risk based therapeutic strategy for unilateral Favorable Histology Wilms Tumor (FH-WT).
  
  
  METHODS
  Thirty-three patients with unilateral WT were treated in two institutions between 1986 and 2010. Twenty-eight patients with FH-WT received primary nephrectomy according to the National Wilms' Tumor Study (NWTS) or the Japanese Wilms' Tumor Study (JWiTS) protocol. Retrospective analyses of the non-relapsed group (n=23) and the relapsed group (n=5) compared age, gender, tumor laterality, tumor weight, initial tumor stage, known histological subtype, chemotherapy (2 or 3 drugs), and any irradiation delivered. Stages and histological subtypes of the tumors were re-evaluated according to the Japanese staging system.
  
  
  RESULTS
  Five of the twenty-eight tumors relapsed, and one patient died. The initial staging (P=0.029) and the histological subtype (P=0.003) were the only factors indicating relapse. Nine of the twenty-three tumors were histologically classified as blastemal predominant subtype (BPT-WT). Five relapsed.
  
  
  CONCLUSIONS
  According to the basic Japanese therapeutic strategy, all patients underwent a primary nephrectomy before chemotherapy. This study suggests that the histological subtype pre-treatment "BPT-WT" should be included as a strong indicator of poor prognosis. Such patients should be treated as a high-risk group.
authors.affiliation: Department of Pediatric Surgery, Shizuoka Children's Hospital, Shizuoka, Japan. t2aoba@marianna-u.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aoba
authors.forename: Naoto
authors.initials: N
authors.lastname: Urushihara
authors.forename: Koji
authors.initials: K
authors.lastname: Fukumoto
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Furuta
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Fukuzawa
authors.forename: Maki
authors.initials: M
authors.lastname: Mitsunaga
authors.forename: Kentaro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Masaya
authors.initials: M
authors.lastname: Yamoto
authors.forename: Hiromu
authors.initials: H
authors.lastname: Miyake
authors.forename: Mariko
authors.initials: M
authors.lastname: Koyama
authors.forename: Hideto
authors.initials: H
authors.lastname: Iwabuchi
authors.forename: Junki
authors.initials: J
authors.lastname: Koike
authors.forename: Shinobu
authors.initials: S
authors.lastname: Tatsunami
authors.forename: Munechika
authors.initials: M
authors.lastname: Wakisaka
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kitagawa
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D001707:Biopsy, Needle; D017024:Chemotherapy, Adjuvant; D002675:Child, Preschool; D015331:Cohort Studies; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007564:Japan; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000379:methods* / Q000401:mortality; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D016896:Treatment Outcome; D009396:Wilms Tumor / Q000401:mortality / Q000473:pathology* / Q000628:therapy*