title: HER2 and TOP2A in high-risk early breast cancer patients treated with adjuvant epirubicin-based dose-dense sequential chemotherapy.
abstract: BACKGROUND
  HER2 and TOP2A parameters (gene status, mRNA and protein expression) have individually been associated with the outcome of patients treated with anthracyclines. The aim of this study was to comprehensively evaluate the prognostic/predictive significance of the above parameters in early, high-risk breast cancer patients treated with epirubicin-based, dose-dense sequential adjuvant chemotherapy.
  
  
  METHODS
  In a series of 352 breast carcinoma tissues from patients that had been post-operatively treated with epirubicin-CMF with or without paclitaxel, we assessed HER2 and TOP2A gene status (chromogenic in situ hybridization), mRNA expression (quantitative reverse transcription PCR), as well as HER2 and TopoIIa protein expression (immunohistochemistry).
  
  
  RESULTS
  HER2 and TOP2A amplification did not share the same effects on their downstream molecules, with consistent patterns observed in HER2 mRNA and protein expression according to HER2 amplification (all parameters strongly inter-related, p values < 0.001), but inconsistent patterns in the case of TOP2A. TOP2A gene amplification (7% of all cases) was not related to TOP2A mRNA and TopoIIa protein expression, while TOP2A mRNA and TopoIIa protein were strongly related to each other (p < 0.001). Hence, TOP2A amplified tumors did not correspond to tumors with high TOP2A mRNA or TopoIIa protein expression, while the latter were characterized by high Ki67 scores (p = 0.003 and p < 0.001, respectively). Multivariate analysis adjusted for nodal involvement, hormone receptor status, Ki67 score and HER2/TOP2A parameters revealed HER2/TOP2A co-amplification (21.2% of HER2 amplified tumors) as an independent favorable prognostic factor for DFS (HR = 0.13, 95% CI: 0.02-0.96, p = 0.046); in contrast, increased HER2/TOP2A mRNA co-expression was identified as an independent adverse prognostic factor for both DFS (HR = 2.41, 95% CI: 1.31-4.42, p = 0.005) and OS (HR = 2.83, 95% CI: 1.42-5.63, p = 0.003), while high TOP2A mRNA expression was an independent adverse prognostic factor for OS (HR = 2.06, 95% CI: 1.23-3.46, p = 0.006). None of the parameters tested was associated with response to paclitaxel.
  
  
  CONCLUSIONS
  This study confirms the favorable prognostic value of HER2/TOP2A co-amplification and the adverse prognostic value of high TOP2A mRNA expression extending it to the adjuvant treatment setting in early high-risk breast cancer. The strong adverse prognostic impact of high HER2/TOP2A mRNA co-expression needs further validation in studies designed to evaluate markers predictive for anthracyclines.
  
  
  BACKGROUND
  Australian New Zealand Clinical Trials Registry ACTRN12611000506998.
authors.affiliation: Department of Medical Oncology, Papageorgiou Hospital, Aristotle University of Thessaloniki School of Medicine, Thessaloniki, Greece. fountzil@auth.gr
authors.forename: George
authors.initials: G
authors.lastname: Fountzilas
authors.forename: Christos
authors.initials: C
authors.lastname: Valavanis
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Kotoula
authors.forename: Anastasia G
authors.initials: AG
authors.lastname: Eleftheraki
authors.forename: Konstantine T
authors.initials: KT
authors.lastname: Kalogeras
authors.forename: Olympia
authors.initials: O
authors.lastname: Tzaida
authors.forename: Anna
authors.initials: A
authors.lastname: Batistatou
authors.forename: Ralf
authors.initials: R
authors.lastname: Kronenwett
authors.forename: Ralph M
authors.initials: RM
authors.lastname: Wirtz
authors.forename: Mattheos
authors.initials: M
authors.lastname: Bobos
authors.forename: Eleni
authors.initials: E
authors.lastname: Timotheadou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Soupos
authors.forename: George
authors.initials: G
authors.lastname: Pentheroudakis
authors.forename: Helen
authors.initials: H
authors.lastname: Gogas
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Vlachodimitropoulos
authors.forename: Genovefa
authors.initials: G
authors.lastname: Polychronidou
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Aravantinos
authors.forename: Angelos
authors.initials: A
authors.lastname: Koutras
authors.forename: Christos
authors.initials: C
authors.lastname: Christodoulou
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Pectasides
authors.forename: Petroula
authors.initials: P
authors.lastname: Arapantoni
mesh_terms: D000328:Adult; D000368:Aged; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology / Q000627:therapeutic use*; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015251:Epirubicin / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D052138:Genes, Neoplasm / Q000235:genetics; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008875:Middle Aged; D015999:Multivariate Analysis; D016612:Paraffin Embedding; D000075223:Poly-ADP-Ribose Binding Proteins; D016016:Proportional Hazards Models; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012307:Risk Factors; D016707:Tissue Fixation; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000903:Antibiotics, Antineoplastic; D000951:Antigens, Neoplasm; D004250:DNA Topoisomerases, Type II; D004268:DNA-Binding Proteins; D015251:Epirubicin; D019394:Ki-67 Antigen; D000075223:Poly-ADP-Ribose Binding Proteins; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human; C000618811:TOP2A protein, human