title: Genomic and immunophenotypical characterization of pure micropapillary carcinomas of the breast.
abstract: Pure invasive micropapillary carcinoma (MPC) is a special histological type that accounts for 0.7-3% of all breast cancers. MPC has a distinctive growth pattern and a more aggressive clinical behaviour than invasive ductal carcinomas of no special type (IDC-NSTs). To define the molecular characteristics of MPCs, we profiled a series of 12 MPCs and 24 grade and oestrogen receptor (ER)-matched IDC-NSTs using high-resolution microarray comparative genomic hybridization (aCGH). In addition, we generated a tissue microarray containing a series of 24 MPCs and performed immunohistochemical analysis with ER, PR, Ki-67, HER2, CK5/6, CK14, CK17, EGFR, topoisomerase-IIalpha, cyclin D1, caveolin-1, E-cadherin, and beta-catenin antibodies. In situ hybridization probes were employed to evaluate the prevalence of amplification of HER2, TOP2A, EGFR, CCND1, MYC, ESR1, and FGFR1 genes. aCGH analysis demonstrated that MPCs significantly differed from IDC-NSTs at the genomic level. Gains of 1q, 2q, 4p, 6p, 6q23.2-q27, 7p, 7q, 8p, 8q, 9p, 10p, 11q, 12p, 12q, 16p, 17p, 17q, 19p, 20p, 20q, and 21q, and losses of 1p, 2p, 6q11.1-q16.3, 6q21-q22.1, 9p, 11p, 15q, and 19q were more prevalent in MPCs. High-level gains/amplifications of 8p12-p11, 8q12, 8q13, 8q21, 8q23, 8q24, 17q21, 17q23, and 20q13 were significantly associated with MPCs. A comparison between 24 MPCs and a series of 48 grade and ER-matched IDC-NSTs revealed that high cyclin D1 expression, high proliferation rates, and MYC (8q24) amplification were significantly associated with MPCs. Our results demonstrate that MPCs have distinct histological features and molecular genetic profiles supporting the contention that they constitute a distinct pathological entity.
authors.affiliation: The Breakthrough Breast Cancer Research Centre--Institute of Cancer Research, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Marchiò
authors.forename: M
authors.initials: M
authors.lastname: Iravani
authors.forename: R
authors.initials: R
authors.lastname: Natrajan
authors.forename: M B
authors.initials: MB
authors.lastname: Lambros
authors.forename: K
authors.initials: K
authors.lastname: Savage
authors.forename: N
authors.initials: N
authors.lastname: Tamber
authors.forename: K
authors.initials: K
authors.lastname: Fenwick
authors.forename: A
authors.initials: A
authors.lastname: Mackay
authors.forename: R
authors.initials: R
authors.lastname: Senetta
authors.forename: S
authors.initials: S
authors.lastname: Di Palma
authors.forename: F C
authors.initials: FC
authors.lastname: Schmitt
authors.forename: G
authors.initials: G
authors.lastname: Bussolati
authors.forename: L O
authors.initials: LO
authors.lastname: Ellis
authors.forename: A
authors.initials: A
authors.lastname: Ashworth
authors.forename: A
authors.initials: A
authors.lastname: Sapino
authors.forename: J S
authors.initials: JS
authors.lastname: Reis-Filho
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000276:immunology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000276:immunology; D019938:Cyclin D1 / Q000235:genetics; D018450:Disease Progression; D005260:Female; D005784:Gene Amplification; D020869:Gene Expression Profiling / Q000379:methods*; D005819:Genetic Markers; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D020411:Oligonucleotide Array Sequence Analysis; D009857:Oncogenes
chemical_list: D005819:Genetic Markers; D019938:Cyclin D1