title: Gene expression analysis reveals a different transcriptomic landscape in female and male breast cancer.
abstract: Male breast cancer (MBC) is a poorly characterized disease because of its rarity. Clinical management is based on results obtained from randomized trials conducted in women notwithstanding data in the literature suggesting relevant gender-associated differences in terms of biological and clinical behavior. However, a genome-wide characterization of MBC on a transcriptional level is lacking. In this study, gene expression profiles of 37 estrogen receptor positive (ER+) MBC specimens were compared to that of 53 ER+ Female Breast Cancer (FBC) samples similar for clinical and patho-biological features. Almost 1000 genes were found differentially expressed (FDR < 1%) between female and male patients and biological interpretation highlighted a gender-associated modulation of key biological processes ranging from energy metabolism to regulation of translation and matrix remodeling as well as immune system recruitment. Moreover, an analysis of genes correlated to steroid receptors and ERBB2 suggested a prominent role for the androgen receptor in MBC with a minor relevance for progesterone receptor and ERBB2, although, similarly to FBC, a genomic amplification could be observed. Our findings support the idea that breast cancer is a quite different disease in male and female patients and the underlying gender-related biological differences are likely to have clinical implications connected with different susceptibility to treatment.
authors.affiliation: Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via Amadeo 42, 20133 Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Callari
authors.forename: Vera
authors.initials: V
authors.lastname: Cappelletti
authors.forename: Loris
authors.initials: L
authors.lastname: De Cecco
authors.forename: Valeria
authors.initials: V
authors.lastname: Musella
authors.forename: Patrizia
authors.initials: P
authors.lastname: Miodini
authors.forename: Silvia
authors.initials: S
authors.lastname: Veneroni
authors.forename: Manuela
authors.initials: M
authors.lastname: Gariboldi
authors.forename: Marco Alessandro
authors.initials: MA
authors.lastname: Pierotti
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Daidone
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018567:Breast Neoplasms, Male / Q000235:genetics*; D018925:Chemokines / Q000032:analysis; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D006801:Humans; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics; D011944:Receptors, Androgen / Q000235:genetics; D011980:Receptors, Progesterone / Q000235:genetics; D012737:Sex Factors; D020741:rho GTP-Binding Proteins / Q000032:analysis
chemical_list: D018925:Chemokines; D018719:Erb-b2 Receptor Tyrosine Kinases; D011944:Receptors, Androgen; D011980:Receptors, Progesterone; D020741:rho GTP-Binding Proteins; C508053:ERBB2 protein, human