Comparison of molecular subtype distribution in triple-negative inflammatory and non-inflammatory breast cancers

Hiroko Masuda (1) , Keith Baggerly (1) , Ying Wang (1) , Takayuki Iwamoto , Takae Brewer (1) , Lajos Pusztai (1) , Kazuharu Kai (1) , Takahiro Kogawa (1) , Pascal Finetti (2) , Daniel Birnbaum (2) , Luc Dirix , Wendy Woodward (1) , James Reuben (1) , Savitri Krishnamurthy (1) , W Fraser Symmans (1) , Steven van Laere (3) , François Bertucci (2) , Gabriel Hortobagyi (1) , Naoto Ueno (1)

1 The University of Texas M.D. Anderson Cancer Center [Houston]
2 Institut Paoli-Calmettes
3 KU Leuven - Catholic University of Leuven - Katholieke Universiteit Leuven

Introduction: Because of its high rate of metastasis, inflammatory breast cancer (IBC) has a poor prognosis compared with non-inflammatory types of breast cancer (non-IBC). In a recent study, Lehmann and colleagues identified seven subtypes of triple-negative breast cancer (TNBC). We hypothesized that the distribution of TNBC subtypes differs between TN-IBC and TN-non-IBC. We determined the subtypes and compared clinical outcomes by subtype in TN-IBC and TN-non-IBC patients. Methods: We determined TNBC subtypes in a TNBC cohort from the World IBC Consortium for which IBC status was known (39 cases of TN-IBC; 49 cases of TN-non-IBC). We then determined the associations between TNBC subtypes and IBC status and compared clinical outcomes between TNBC subtypes. Results: We found the seven subtypes exist in both TN-IBC and TN-non-IBC. We found no association between TNBC subtype and IBC status (P = 0.47). TNBC subtype did not predict recurrence-free survival. IBC status was not a significant predictor of recurrence-free or overall survival in the TNBC cohort. Conclusions: Our data show that, like TN-non-IBC, TN-IBC is a heterogeneous disease. Although clinical characteristics differ significantly between IBC and non-IBC, no unique IBC-specific TNBC subtypes were identified by mRNA gene-expression profiles of the tumor. Studies are needed to identify the subtle molecular or microenvironmental differences that contribute to the differing clinical behaviors between TN-IBC and TN-non-IBC.

Domains: Life Sciences [q-bio]; Cancer

Hiroko Masuda, Keith Baggerly, Ying Wang, Takayuki Iwamoto, Takae Brewer, et al.. Comparison of molecular subtype distribution in triple-negative inflammatory and non-inflammatory breast cancers. Breast Cancer Research, 2013, 15 (6), pp.R112. ⟨10.1186/bcr3579⟩. ⟨hal-03623763⟩