title: [Effects of polysomy 17 on HER-2 gene and protein expression and its clinicopathologic significance in breast cancer].
abstract: OBJECTIVE
  To explore the effects of polysomy 17 on human epidermal growth factor receptor-2 (HER-2) testing and study its clinicopathologic significance.
  
  
  METHODS
  We retrospectively analyzed the HER-2 status by fluorescence in situ hybridization (FISH) and HER-2 protein expression by immunohistochemistry (IHC) in a cohort of 619 patients with invasive breast cancer. The relationship between polysomy 17 and various clinicopathologic parameters was assessed.
  
  
  RESULTS
  Polysomy 17 was observed in 31.8% of cases, but more frequently in the IHC(3+) (41.9%) than in the IHC(2+)(27.7%) and IHC(1+/0) (11.1%) subgroup (P = 0.001). There was no significant correlation between the frequency of polysomy 17 and HER-2 status in each IHC subgroup (P > 0.05). Among the cases without gene amplification by FISH, 9 of 15 IHC(3+) cases showed polysomy 17. As compared with the amplified group, un-amplified polysomy 17 patients were associated with such good prognostic indicators as greater hormone receptor positivity (P < 0.001) and lower Ki-67 index (P = 0.003) with a trend towards those with neither amplification or polysomy.
  
  
  CONCLUSIONS
  The frequency of polysomy 17 is partially correlated with HER-2 protein expression but not HER-2 amplification. And polysomy 17 is a major factor in strong HER-2 protein overexpression in 3+ non amplified cases. Tumors displaying un-amplified polysomy 17 resemble more HER-2-negative than HER-2-positive counterparts.
authors: Department of Medical Oncology, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors: Jian
authors: J
authors: Li
authors: Bing-he
authors: BH
authors: Xu
authors: Jia-yu
authors: JY
authors: Wang
authors: Qing
authors: Q
authors: Li
authors: Pin
authors: P
authors: Zhang
authors: Peng
authors: P
authors: Yuan
authors: Fei
authors: F
authors: Ma
authors: Ying
authors: Y
authors: Fan
authors: Rui-gang
authors: RG
authors: Cai
authors: Qiao
authors: Q
authors: Li
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002869:Chromosome Aberrations; D002886:Chromosomes, Human, Pair 17; D005260:Female; D006801:Humans; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human