title: Comparative genomic hybridization analysis reveals new different subgroups in early-stage bladder tumors.
abstract: OBJECTIVE
  To classify bladder tumors according to their genomic imbalances and evaluate their association with patient's outcome.
  
  
  METHODS
  Sixty-three superficially and minimally invasive bladder tumors were analyzed by conventional comparative genomic hybridization. Subtelomeric screening in 15 of these tumors was performed by multiplex ligation-dependent probe amplification.
  
  
  RESULTS
  Losses of 9q and 9p (32% and 25% of all cases, respectively) as well as gains of chromosomes Xq and Xp (28% and 25%, respectively) were the most frequent chromosome imbalances. Losses of 8p and gains in 1q and 8q were detected in >20% of cases. Tumors were classified into 3 groups according to their individualized pattern of gains and losses. The largest group was characterized by few chromosome imbalances, presenting 77% and 49% of the Ta and T1 tumors, respectively. Another group characterized by chromosomal gains, was composed of equal number of Ta and T1 tumors, with +1q and +17q gains being the most common imbalances. A minority group was characterized by chromosomal losses on 11q, 5q, and 6q. The multiplex ligation-dependent probe amplification study showed good correlation with comparative genomic hybridization results. With regard to the biological significance of this classification, a remarkable fact is that this minority group composed mainly of T1 tumors, showed a significant decrease in patient overall survival.
  
  
  CONCLUSIONS
  Our data suggest that superficial carcinomas of the bladder can be subdivided into a larger number of subclasses than had previously been expected. Our results also demonstrate a decreased survival among patients whose tumors show more genomic losses than gains.
authors: Institut de Biotecnologia i Biomedicina and Department de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Esther
authors: E
authors: Prat
authors: Javier
authors: J
authors: del Rey
authors: Immaculada
authors: I
authors: Ponsa
authors: Marga
authors: M
authors: Nadal
authors: Jordi
authors: J
authors: Camps
authors: Alberto
authors: A
authors: Plaja
authors: Mercedes
authors: M
authors: Campillo
authors: Ferran
authors: F
authors: Algaba
authors: Antoni
authors: A
authors: Gelabert
authors: Rosa
authors: R
authors: Miró
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055028:Comparative Genomic Hybridization; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D001749:Urinary Bladder Neoplasms / Q000145:classification* / Q000235:genetics* / Q000473:pathology