title: Comparative genomic hybridization-based oncogenetic tree model for genetic classification of breast cancer.
abstract: OBJECTIVE
  To describe a genetic progression pathway in breast cancer by a maximum likelihood-based tree model representing the dependencies between chromosomal imbalances.
  
  
  METHODS
  One hundred six cases were studied by comparative genomic hybridization, followed by maximum likelihood estimation of an oncogenetic tree model.
  
  
  RESULTS
  The tree model identified 3 clusters with correlated chromosomal imbalances. The first cluster included losses at 4q, 5q, 6q, 9p, 13q and a gain at 17q; the second cluster included gains at 1q, 8q, 16p and 20q; the third cluster included losses at 8p, 11q, 16q and 18q. The imbalances nearest the root of the tree were the loss at 13q (cluster 1), the gain at 1q (cluster 2) and the loss at 18q (cluster 3), reflecting an early change in breast cancer evolution. Cox regression analysis revealed the tumor stage and the grade as relevant for overall survival (p = 0.001) and the tumor stage, the grade and the loss at 16q as relevant for disease-free survival (p = 0.001).
  
  
  CONCLUSIONS
  Methods like oncogenetic tree analysis provide insights into the genetic progression of breast cancer and may extract relevant markers detected by screening methods like comparative genomic hybridization for further studies.
authors.affiliation: Institute of Pathology, University Hospital "Carl Gustav Carus" Dresden, Germany. katrin.friedrich@uniklinikum-dresden.de
authors.forename: Katrin
authors.initials: K
authors.lastname: Friedrich
authors.forename: Anja
authors.initials: A
authors.lastname: von Heydebreck
authors.forename: Gunter
authors.initials: G
authors.lastname: Haroske
authors.forename: Jens
authors.initials: J
authors.lastname: Scheithauer
authors.forename: Wolfdietrich
authors.initials: W
authors.lastname: Meyer
authors.forename: Klaus Dietmar
authors.initials: KD
authors.lastname: Kunze
authors.forename: Gustavo
authors.initials: G
authors.lastname: Baretton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000145:classification* / Q000235:genetics* / Q000473:pathology; D002869:Chromosome Aberrations; D002877:Chromosomes, Human; D055028:Comparative Genomic Hybridization; D018450:Disease Progression; D005260:Female; D006801:Humans; D008875:Middle Aged; D008957:Models, Genetic; D015233:Models, Statistical; D009367:Neoplasm Staging; D012044:Regression Analysis
chemical_list: D014408:Biomarkers, Tumor