title: Evaluation of chromosome 17 polysomy in breast cancer by FISH analysis of whole nuclei, and its clinicopathological significance.
abstract: Human epidermal growth factor receptor 2 (HER2) amplification and overexpression are associated with poor prognosis and resistance to cytotoxic drugs in patients with breast cancer. Increases in the number of HER2 gene copies have been shown to be associated with chromosome 17 polysomy. The use of whole, intact nuclei for fluorescencein situhybridization (FISH) assay improves the accuracy of the results. FISH analysis of whole nuclei (WNFISH) and immunohistochemistry (IHC) were used to analyze HER2 gene amplification and HER2 protein expression in 109 breast cancer specimens. Chromosome 17 polysomy and its correlations with HER2 gene amplification, HER2 protein expression and the clinicopathological outcomes of the patients were also investigated. Among the 109 cases, WNFISH detected HER2 amplification in 30 cases, equivocal amplification in 19 cases and no amplification in 60 cases. WNFISH detected chromosome 17 centromere (CEP17) polysomy in 37 cases and no polysomy in 72 cases. Among the 109 cases assessed by tissue microarray and IHC, 31 cases were HER2-negative, 14 cases were scored 1+, 23 cases were scored 2+ and 41 cases were scored 3+. The results demonstrated that in the cases with chromosome 17 polysomy, the HER2 gene was amplified, HER2 protein expression was increased and the incidences of nuclear atypia and lymph node metastases were higher compared with those in the cases without chromosome 17 polysomy. Chromosome 17 polysomy may correlate with increased malignant potential and metastatic spread in breast cancer.
authors.affiliation: Department of General Surgery, General Hospital of Shenyang Military Area Command, Shenyang, Liaoning 110840, P.R. China.
authors.forename: Huiyong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Division of Nephrology, Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Bai
authors.affiliation: Department of Gastroenterology, No. 202 Hospital of People's Liberation Army, Shenyang, Liaoning 110003, P.R. China.
authors.forename: Fanjun
authors.initials: F
authors.lastname: Meng
authors.affiliation: Department of General Surgery, General Hospital of Shenyang Military Area Command, Shenyang, Liaoning 110840, P.R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, General Hospital of Shenyang Military Area Command, Shenyang, Liaoning 110840, P.R. China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhang
keywords: HER2 gene; breast cancer; fluorescence in situ hybridization; nuclei microarray