TY - JOUR
T1 - Uncovering the molecular secrets of inflammatory breast cancer biology
T2 - An integrated analysis of three distinct affymetrix gene expression datasets
AU - Van Laere, Steven J.
AU - Ueno, Naoto T.
AU - Finetti, Pascal
AU - Vermeulen, Peter
AU - Lucci, Anthony
AU - Robertson, Fredika M.
AU - Marsan, Melike
AU - Iwamoto, Takayuki
AU - Krishnamurthy, Savitri
AU - Masuda, Hiroko
AU - Van Dam, Peter
AU - Woodward, Wendy A.
AU - Viens, Patrice
AU - Cristofanilli, Massimo
AU - Birnbaum, Daniel
AU - Dirix, Luc
AU - Reuben, James M.
AU - Bertucci, François
PY - 2013/9/1
Y1 - 2013/9/1
N2 - Background: Inflammatory breast cancer (IBC) is a poorly characterized form of breast cancer. So far, the results of expression profiling in IBC are inconclusive due to various reasons including limited sample size. Here, we present the integration of three Affymetrix expression datasets collected through the World IBC Consortium allowing us to interrogate the molecular profile of IBC using the largest series of IBC samples ever reported. Experimental Design: Affymetrix profiles (HGU133-series) from 137 patients with IBC and 252 patients with non-IBC (nIBC) were analyzed using unsupervised and supervised techniques. Samples were classified according to the molecular subtypes using the PAM50-algorithm. Regression models were used to delineate IBC-specific and molecular subtype-independent changes in gene expression, pathway, and transcription factor activation. Results: Four robust IBC-sample clusters were identified, associated with the different molecular subtypes (P < 0.001), all of which were identified in IBC with a similar prevalence as in nIBC, except for the luminal A subtype (19% vs. 42%; P < 0.001) and the HER2-enriched subtype (22% vs. 9%; P < 0.001). Supervised analysis identified and validated an IBC-specific, molecular subtype-independent 79-gene signature, which held independent prognostic value in a series of 871 nIBCs. Functional analysis revealed attenuated TGF-β signaling in IBC. Conclusion: We show that IBC is transcriptionally heterogeneous and that all molecular subtypes described in nIBC are detectable in IBC, albeit with a different frequency. The molecular profile of IBC, bearing molecular traits of aggressive breast tumor biology, shows attenuation of TGF-β signaling, potentially explaining the metastatic potential of IBC tumor cells in an unexpected manner.
AB - Background: Inflammatory breast cancer (IBC) is a poorly characterized form of breast cancer. So far, the results of expression profiling in IBC are inconclusive due to various reasons including limited sample size. Here, we present the integration of three Affymetrix expression datasets collected through the World IBC Consortium allowing us to interrogate the molecular profile of IBC using the largest series of IBC samples ever reported. Experimental Design: Affymetrix profiles (HGU133-series) from 137 patients with IBC and 252 patients with non-IBC (nIBC) were analyzed using unsupervised and supervised techniques. Samples were classified according to the molecular subtypes using the PAM50-algorithm. Regression models were used to delineate IBC-specific and molecular subtype-independent changes in gene expression, pathway, and transcription factor activation. Results: Four robust IBC-sample clusters were identified, associated with the different molecular subtypes (P < 0.001), all of which were identified in IBC with a similar prevalence as in nIBC, except for the luminal A subtype (19% vs. 42%; P < 0.001) and the HER2-enriched subtype (22% vs. 9%; P < 0.001). Supervised analysis identified and validated an IBC-specific, molecular subtype-independent 79-gene signature, which held independent prognostic value in a series of 871 nIBCs. Functional analysis revealed attenuated TGF-β signaling in IBC. Conclusion: We show that IBC is transcriptionally heterogeneous and that all molecular subtypes described in nIBC are detectable in IBC, albeit with a different frequency. The molecular profile of IBC, bearing molecular traits of aggressive breast tumor biology, shows attenuation of TGF-β signaling, potentially explaining the metastatic potential of IBC tumor cells in an unexpected manner.
UR - http://www.scopus.com/inward/record.url?scp=84883483781&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84883483781&partnerID=8YFLogxK
U2 - 10.1158/1078-0432.CCR-12-2549
DO - 10.1158/1078-0432.CCR-12-2549
M3 - Article
C2 - 23396049
AN - SCOPUS:84883483781
SN - 1078-0432
VL - 19
SP - 4685
EP - 4696
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 17
ER -