title: Natural course of low risk neuroblastoma.
abstract: BACKGROUND
  Neuroblastoma is characterized by heterogeneity of histology, biology, and clinical behavior. Most epidemiology studies are based on Western and Japanese populations; there are very few studies on neuroblastoma from Southeast Asia.
  
  
  METHODS
  Cases of Thai children with neuroblastoma were retrospectively reviewed to determine if the epidemiology of the disease differs from Western populations. Sixty-two cases were assembled from two pathology centers in Bangkok. Histologic prognostic category and MYCN copy number were determined.
  
  
  RESULTS
  The median age at diagnosis was 2.9 years. Only 11% of cases presented at less than 1 year of age and 12% cases had low stage disease (1, 2, and 4S). The majority of tumors had unfavorable histology (48/62); this was at least partly due to the higher age at diagnosis for most patients. MYCN amplification was detected in 18/52 (35%) tumors, all in stage 3 or 4 tumors. We assigned patients to high, intermediate and low risk categories using the Children's Oncology Group risk stratification criteria. In contrast to Western studies, the majority of cases (50/59 or 85%) in our series had high risk disease.
  
  
  CONCLUSIONS
  Since there is no evidence to date that the biology of neuroblastoma varies by geographic region, the paucity of low risk cases in our study may reflect spontaneous resolution/differentiation of tumors that are not clinically detected. Moreover, a delay in diagnosis of intermediate risk cases could result in higher tumor burden at the time of diagnosis, increasing the proportion of high risk cases observed.
authors.affiliation: Institute of Pathology, Department of Medical Services, Ministry of Public Health, Bangkok, Thailand.
authors.forename: Somruetai
authors.initials: S
authors.lastname: Shuangshoti
authors.forename: Shanop
authors.initials: S
authors.lastname: Shuangshoti
authors.forename: Issarang
authors.initials: I
authors.lastname: Nuchprayoon
authors.forename: Somjai
authors.initials: S
authors.lastname: Kanjanapongkul
authors.forename: Paula
authors.initials: P
authors.lastname: Marrano
authors.forename: Meredith S
authors.initials: MS
authors.lastname: Irwin
authors.forename: Paul S
authors.initials: PS
authors.lastname: Thorner
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D000071447:N-Myc Proto-Oncogene Protein; D009447:Neuroblastoma / Q000209:etiology / Q000235:genetics / Q000401:mortality*; D009687:Nuclear Proteins / Q000235:genetics; D015513:Oncogene Proteins / Q000235:genetics; D012306:Risk; D013785:Thailand / Q000453:epidemiology
chemical_list: C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins