title: Genomic and expression analysis of microdissected inflammatory breast cancer.
abstract: Inflammatory breast cancer (IBC) is a unique clinical entity characterized by rapid onset of erythema and swelling of the breast often without an obvious breast mass. Many studies have examined and compared gene expression between IBC and non-IBC (nIBC), repeatedly finding clusters associated with receptor subtype, but no consistent gene signature associated with IBC has been validated. Here we compared microdissected IBC tumor cells to microdissected nIBC tumor cells matched based on estrogen and HER-2/neu receptor status. Gene expression analysis and comparative genomic hybridization were performed. An IBC gene set and genomic set were identified using a training set and validated on the remaining data. The IBC gene set was further tested using data from IBC consortium samples and publicly available data. Receptor driven clusters were identified in IBC; however, no IBC-specific gene signature was identified. Fifteen genes were correlated between increased genomic copy number and gene overexpression data. An expression-guided gene set upregulated in the IBC training set clustered the validation set into two clusters independent of receptor subtype but segregated only 75 % of samples in each group into IBC or nIBC. In a larger consortium cohort and in published data, the gene set failed to optimally enrich for IBC samples. However, this gene set had a high negative predictive value for excluding the diagnosis of IBC in publicly available data (100 %). An IBC enriched genomic data set accurately identified 10/16 cases in the validation data set. Even with microdissection, no IBC-specific gene signature distinguishes IBC from nIBC. Using microdissected data, a validated gene set was identified that is associated with IBC tumor cells. Inflammatory breast cancer comparative genomic hybridization data are presented, but a validated genomic data set that identifies IBC is not demonstrated.
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Woodward
authors.forename: Savitri
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Hideko
authors.initials: H
authors.lastname: Yamauchi
authors.forename: Randa
authors.initials: R
authors.lastname: El-Zein
authors.forename: Dai
authors.initials: D
authors.lastname: Ogura
authors.forename: Eri
authors.initials: E
authors.lastname: Kitadai
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Niwa
authors.forename: Massimo
authors.initials: M
authors.lastname: Cristofanilli
authors.forename: Peter
authors.initials: P
authors.lastname: Vermeulen
authors.forename: Luc
authors.initials: L
authors.lastname: Dirix
authors.forename: Patrice
authors.initials: P
authors.lastname: Viens
authors.forename: Steve
authors.initials: S
authors.lastname: van Laere
authors.forename: François
authors.initials: F
authors.lastname: Bertucci
authors.forename: James M
authors.initials: JM
authors.lastname: Reuben
authors.forename: Naoto T
authors.initials: NT
authors.lastname: Ueno
mesh_terms: D015331:Cohort Studies; D055028:Comparative Genomic Hybridization; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D015894:Genome, Human; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D042282:Microdissection; D011237:Predictive Value of Tests; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human