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Series GSE21653 Query DataSets for GSE21653
Status Public on May 05, 2010
Title A gene expression signature identifies two prognostic subgroups of basal breast cancer
Organism Homo sapiens
Experiment type Expression profiling by array
Summary Medullary breast cancers (MBC) display a basal profile, but a favorable prognosis. We hypothesized that a previously published 368-gene expression signature associated with MBC might serve to define a prognostic classifier in basal cancers. We collected public gene expression and histoclinical data of 2145 invasive early breast adenocarcinomas. We developed a Support Vector Machine (SVM) classifier based on this 368-gene list in a learning set, and tested its predictive performances in an independent validation set. Then, we assessed its prognostic value and that of six prognostic signatures for disease-free survival (DFS) in the remaining 2034 samples. The SVM model accurately classified all MBC samples in the learning and validation sets. A total of 466 cases were basal across other sets. The SVM classifier separated them into two subgroups, subgroup 1 (resembling MBC) and subgroup 2 (not resembling MBC). Subgroup 1 exhibited 71% 5-year DFS, whereas subgroup 2 exhibited 50% (p=9.93E-05). The classifier outperformed the classical prognostic variables in multivariate analysis, conferring lesser risk for relapse in subgroup 1 (HR=0.52, p=3.9E-04). This prognostic value was specific to the basal subtype, in which none of the other prognostic signatures was informative.
 
Overall design The IPC series contained frozen tumor samples obtained from 266 early breast cancer patients who underwent initial surgery in our institution between 1992 and 2004. They included 227 cases previously reported {Finetti, 2008 #1758} and 39 additional cases, all similarly profiled using Affymetrix U133 Plus 2.0 human oligonucleotide microarrays as previously described {Finetti, 2008 #1758}. The study was approved by the IPC review board, and informed consent was available for each case. Gene expression data of 266 BCs were quantified by using whole-genome DNA microarrays (HG-U133 plus 2.0, Affymetrix).
 
Contributor(s) Sabatier R, Finetti P, Cervera N, Lambaudie E, Esterni B, Mamessier E, Tallet A, Chabannon C, Extra J, Jacquemier J, Viens P, Birnbaum D, Bertucci F
Citation(s) 20490655, 22110708
Submission date May 04, 2010
Last update date Mar 25, 2019
Contact name Pascal FINETTI
E-mail(s) finettip@ipc.unicancer.fnclcc.fr
Phone (33)+4 91 22 33 04
Organization name Institut Paoli-Calmettes
Department Centre de cancérologie de Marseille
Lab Molecular Oncology
Street address 232 Bd Ste Marguerite
City Marseille
State/province BdR
ZIP/Postal code 13009
Country France
 
Platforms (1)
GPL570 [HG-U133_Plus_2] Affymetrix Human Genome U133 Plus 2.0 Array
Samples (266)
GSM540108 BC1
GSM540109 BC2
GSM540110 BC3
Relations
BioProject PRJNA125879

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE21653_RAW.tar 1.2 Gb (http)(custom) TAR (of CEL)
Processed data included within Sample table

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