title: Clustering cancer gene expression data: a comparative study.
abstract: BACKGROUND
  The use of clustering methods for the discovery of cancer subtypes has drawn a great deal of attention in the scientific community. While bioinformaticians have proposed new clustering methods that take advantage of characteristics of the gene expression data, the medical community has a preference for using "classic" clustering methods. There have been no studies thus far performing a large-scale evaluation of different clustering methods in this context.
  
  
  CONCLUSIONS
  We present the first large-scale analysis of seven different clustering methods and four proximity measures for the analysis of 35 cancer gene expression data sets. Our results reveal that the finite mixture of Gaussians, followed closely by k-means, exhibited the best performance in terms of recovering the true structure of the data sets. These methods also exhibited, on average, the smallest difference between the actual number of classes in the data sets and the best number of clusters as indicated by our validation criteria. Furthermore, hierarchical methods, which have been widely used by the medical community, exhibited a poorer recovery performance than that of the other methods evaluated. Moreover, as a stable basis for the assessment and comparison of different clustering methods for cancer gene expression data, this study provides a common group of data sets (benchmark data sets) to be shared among researchers and used for comparisons with new methods. The data sets analyzed in this study are available at http://algorithmics.molgen.mpg.de/Supplements/CompCancer/.
authors.affiliation: Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Berlin, Germany. marcilio@dimap.ufrn.br
authors.forename: Marcilio C P
authors.initials: MC
authors.lastname: de Souto
authors.forename: Ivan G
authors.initials: IG
authors.lastname: Costa
authors.forename: Daniel S A
authors.initials: DS
authors.lastname: de Araujo
authors.forename: Teresa B
authors.initials: TB
authors.lastname: Ludermir
authors.forename: Alexander
authors.initials: A
authors.lastname: Schliep
mesh_terms: D000465:Algorithms; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods*; D018076:DNA, Complementary / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D005810:Multigene Family; D009369:Neoplasms / Q000175:diagnosis* / Q000235:genetics; D016011:Normal Distribution; D020411:Oligonucleotide Array Sequence Analysis; D010363:Pattern Recognition, Automated / Q000379:methods
chemical_list: D018076:DNA, Complementary