title: Alterations in circulating miRNA levels following early-stage estrogen receptor-positive breast cancer resection in post-menopausal women.
abstract: BACKGROUND
  Circulating microRNAs (miRNAs) exhibit remarkable stability and may serve as biomarkers in several clinical cancer settings. The aim of this study was to investigate changes in the levels of specific circulating miRNA following breast cancer surgery and evaluate whether these alterations were also observed in an independent data set.
  
  
  METHODS
  Global miRNA analysis was performed on prospectively collected serum samples from 24 post-menopausal women with estrogen receptor-positive early-stage breast cancer before surgery and 3 weeks after tumor resection using global LNA-based quantitative real-time PCR (qPCR).
  
  
  RESULTS
  Numbers of specific miRNAs detected in the samples ranged from 142 to 161, with 107 miRNAs detectable in all samples. After correction for multiple comparisons, 3 circulating miRNAs (miR-338-3p, miR-223 and miR-148a) exhibited significantly lower, and 1 miRNA (miR-107) higher levels in post-operative vs. pre-operative samples (p<0.05). No miRNAs were consistently undetectable in the post-operative samples compared to the pre-operative samples. Subsequently, our findings were compared to a dataset from a comparable patient population analyzed using similar study design and the same qPCR profiling platform, resulting in limited agreement.
  
  
  CONCLUSIONS
  A panel of 4 circulating miRNAs exhibited significantly altered levels following radical resection of primary ER+ breast cancers in post-menopausal women. These specific miRNAs may be involved in tumorigenesis and could potentially be used to monitor whether all cancer cells have been removed at surgery and/or, subsequently, whether the patients develop recurrence.
authors.affiliation: Department of Oncology, Odense University Hospital and University of Southern Denmark, Odense, Denmark.
authors.forename: Annette R
authors.initials: AR
authors.lastname: Kodahl
authors.affiliation: Department of Surgery Z, Odense University Hospital, Odense, Denmark.
authors.forename: Pernille
authors.initials: P
authors.lastname: Zeuthen
authors.affiliation: Institute of Medical Biostatistics, Epidemiology and Informatics (IMBEI), Johannes Gutenberg University, Mainz, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Binder
authors.affiliation: Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Ann S
authors.initials: AS
authors.lastname: Knoop
authors.affiliation: Department of Oncology, Odense University Hospital and University of Southern Denmark, Odense, Denmark; Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
authors.forename: Henrik J
authors.initials: HJ
authors.lastname: Ditzel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000097:blood* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D035683:MicroRNAs / Q000097:blood*; D008875:Middle Aged; D009367:Neoplasm Staging; D017698:Postmenopause; D011184:Postoperative Period; D011960:Receptors, Estrogen / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; D011960:Receptors, Estrogen