title: [Molecular genetic abnormalities of N-myc and C-myc in pediatric neuroblastic tumors and clinical pathologic significance].
abstract: OBJECTIVE
  To investigate the molecular genetic abnormalities of N-myc and C-myc, and their clinical pathological implications in pediatric neuroblastic tumors (NTs).
  
  
  METHODS
  Abnormalities of N-myc were detected by interphase fluorescence in situ hybridization (FISH) technique in 246 cases of NTs, including neuroblastoma (NB,188 cases), ganglioneuroblastoma (GNB, 52 cases), ganglioneuroma (GN, 6 cases), and their association with the histological typing of the tumors and prognosis was analyzed. Abnormalities of C-myc were detected by FISH in 133 cases of NTs.
  
  
  RESULTS
  Of the 246 cases of NTs, N-myc amplification was only found in 27 cases (11.0%, 27/246) of NB, but not in any cases of GNB or GN (P < 0.05). 89.0% (219/246) N-myc non-amplification were found in NTs, and it included N-myc gain in 175 cases (71.1%, 175/246) and normal N-myc in 44 cases (17.9%, 44/246). Univariate analysis indicated significantly (P = 0.012) poorer outcome in patients with N-myc amplification than N-myc non-amplification. However no significant difference was observed between N-myc gain cases and normal N-myc cases (P = 0.057). C-myc gain was found in 74 of 133 cases (55.6%) of NTs; no C-myc amplification or translocation was detected. Forty percent (6/15) of cases with N-myc amplification and 57.6% (68/118) of cases with N-myc non-amplification were accompanied by C-myc gain. The difference between N-myc amplification and non-amplification with C-myc gain was not significant (P > 0.05). Univariate analysis indicated that the outcome difference was not statistically significant between C-myc gain cases and normal C-myc cases (P = 0.357).
  
  
  CONCLUSIONS
  The incidence of N-myc amplification only found in NB is low in pediatric NTs in China. Patients with N-myc amplification predict poorer outcome. No amplification or translocation of C-myc is detected in NTs, whereas C-myc gain is relatively common in NTs. There is no obvious association between N-myc amplification and C-myc gain.
authors.affiliation: Department of Pathology, Basic Medical College, Capital Medical University, Beijing, China.
authors.forename: Rong-qin
authors.initials: RQ
authors.lastname: Cai
authors.forename: Chun-ju
authors.initials: CJ
authors.lastname: Zhou
authors.forename: Qin-nuan
authors.initials: QN
authors.lastname: Sun
authors.forename: Xiao-li
authors.initials: XL
authors.lastname: Ma
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Da-ye
authors.initials: DY
authors.lastname: Wang
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Gong
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000235:genetics / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D018305:Ganglioneuroblastoma / Q000235:genetics / Q000473:pathology; D005729:Ganglioneuroma / Q000235:genetics / Q000473:pathology; D005784:Gene Amplification; D016259:Genes, myc; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D008479:Mediastinal Neoplasms / Q000235:genetics / Q000473:pathology; D009447:Neuroblastoma / Q000235:genetics / Q000473:pathology*; D015996:Survival Rate