title: Comparison of the RNA-based EndoPredict multigene test between core biopsies and corresponding surgical breast cancer sections.
abstract: OBJECTIVE
  This study compared the perfomance of the RNA-based EndoPredict multigene test on core biopsies and surgical breast cancer specimens and analysed the influence of biopsy-induced tissue injuries on the test result.
  
  
  METHODS
  80 formalin-fixed paraffin-embedded samples comprising paired biopsies and surgical specimens from 40 ER-positive, HER2-negative patients were evaluated. Total RNA was extracted and the EndoPredict score was determined.
  
  
  RESULTS
  RNA yield was considerably lower in core biopsies, but sufficient to measure the assay in all samples. The EndoPredict score was highly correlated between paired samples (Pearson r=0.92), with an excellent concordance of classification into a low or high risk of metastasis (overall agreement 95%).
  
  
  CONCLUSIONS
  The measurements are comparable between core biopsies and surgical sections, which suggest that the EndoPredict assay can be performed on core biopsy tissue. Inflammatory changes induced by presurgical biopsies had no significant effect on the RNA-based risk assessment in surgical specimens.
authors.affiliation: Institute of Pathology, Charité-Universitätsmedizin Berlin, Berlin, Germany. berit.mueller@charite.de
authors.forename: Berit Maria
authors.initials: BM
authors.lastname: Müller
authors.forename: Jan C
authors.initials: JC
authors.lastname: Brase
authors.forename: Franziska
authors.initials: F
authors.lastname: Haufe
authors.forename: Karsten E
authors.initials: KE
authors.lastname: Weber
authors.forename: Jan
authors.initials: J
authors.lastname: Budzies
authors.forename: Christoph
authors.initials: C
authors.lastname: Petry
authors.forename: Judith
authors.initials: J
authors.lastname: Prinzler
authors.forename: Ralf
authors.initials: R
authors.lastname: Kronenwett
authors.forename: Manfred
authors.initials: M
authors.lastname: Dietel
authors.forename: Carsten
authors.initials: C
authors.lastname: Denkert
mesh_terms: D001706:Biopsy / Q000009:adverse effects; D001940:Breast / Q000293:injuries / Q000473:pathology*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000601:surgery*; D044584:Carcinoma, Ductal / Q000235:genetics / Q000378:metabolism / Q000601:surgery; D018275:Carcinoma, Lobular / Q000235:genetics / Q000378:metabolism / Q000601:surgery; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D005810:Multigene Family / Q000235:genetics*; D012334:RNA, Neoplasm / Q000235:genetics* / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism; D012189:Retrospective Studies; D018570:Risk Assessment
chemical_list: D012334:RNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human