title: Transcriptomic and genomic features of invasive lobular breast cancer.
abstract: Accounting for 10-15% of all breast neoplasms, invasive lobular breast cancer (ILC) is the second most common histological subtype of breast cancer after invasive ductal breast cancer (IDC). Understanding ILC biology, which differs from IDC in terms of clinical presentation, treatment response, relapse timing and patterns, is essential in order to adopt novel, disease-specific management strategies. While the contribution of the histological subtypes to tumour biology has been poorly investigated and acknowledged in the past, recently several major, independent efforts have led to the assembly and molecular characterization of well-annotated ILC case sets. In this review, we provide a critical overview of the literature exploring ILC, through comprehensive and multiomic methods. The first part specifically focuses on ILC transcriptomic features by reviewing the intrinsic molecular subtypes, the application of gene expression scores for the prediction of recurrence, and the identification of gene expression subtypes. The second part describes the main research efforts that lead to the identification of the genomic landscape of ILC, with a special focus to findings that differentiate ILC from IDC and carry potential clinical relevance.
authors.affiliation: Breast Cancer Translational Research Laboratory J.-C. Heuson, Université Libre de Bruxelles, Institut Jules Bordet, 1000 Brussels, Belgium. Electronic address: christine.desmedt@bordet.be.
authors.forename: Christine
authors.initials: C
authors.lastname: Desmedt
authors.affiliation: Department of Internal Medicine (DiMI), University of Genoa and Istituto di Ricovero e Cura a Carattere Scientifico San Martino-National Cancer Institute, Genoa, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Zoppoli
authors.affiliation: Breast Cancer Translational Research Laboratory J.-C. Heuson, Université Libre de Bruxelles, Institut Jules Bordet, 1000 Brussels, Belgium.
authors.forename: Christos
authors.initials: C
authors.lastname: Sotiriou
authors.affiliation: Breast Cancer Translational Research Laboratory J.-C. Heuson, Université Libre de Bruxelles, Institut Jules Bordet, 1000 Brussels, Belgium; Department of Pathology/TCRU, Sint Augustinus, Wilrijk, Belgium.
authors.forename: Roberto
authors.initials: R
authors.lastname: Salgado
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D018275:Carcinoma, Lobular / Q000235:genetics* / Q000473:pathology; D005260:Female; D015894:Genome, Human; D023281:Genomics; D006801:Humans; D009361:Neoplasm Invasiveness / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D059467:Transcriptome / Q000235:genetics*
keywords: Gene expression; Immune; Intrinsic subtypes; Invasive lobular breast cancer; Prognostic classifiers; Proteomics; Sequencing; mutations