title: DNA promoter hypermethylation in nipple fluid: a potential tool for early breast cancer detection.
abstract: BACKGROUND
  Nipple fluid aspiration provides direct non-invasive sampling of fluid from the mammary ductal system, where the majority of breast cancers originate. DNA promoter hypermethylation ("methylation") occurs early and at high frequency in breast carcinogenesis, bearing the potential as a biomarker for cancer detection at its earliest stages. We assessed methylation in nipple fluid from breasts of healthy women, of women with sporadic breast cancer and of their contralateral breasts. Our goal was to investigate whether nipple fluid can be used as a reliable methylation biomarker source.
  
  
  METHODS
  Methylation levels of 13 genes were analysed by quantitative multiplex-methylation specific PCR (QM-MSP) in nipple fluid samples from breasts of healthy women, and from the affected and contralateral breasts of breast cancer patients.
  
  
  RESULTS
  Methylation analysis of the low-volume nipple fluid samples was feasible. Despite the generally low methylation levels, cancerous and healthy breasts nipple fluid could be discriminated with an area under the receiver operating characteristic curve (AUC) of 0.64 (p<0.01) based on a multivariate model including AKR1B1, ALX1, RASSF1A and TM6SF1. Within-patient differences between cancerous and contralateral nipple fluid samples were less prominent.
  
  
  CONCLUSIONS
  Cancerous nipple fluid contains increased levels of methylation of tumor suppressor genes that potentially could serve as a biomarker for early breast cancer detection.
authors.affiliation: Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Jolien S
authors.initials: JS
authors.lastname: de Groot
authors.affiliation: Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Cathy B
authors.initials: CB
authors.lastname: Moelans
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Sjoerd G
authors.initials: SG
authors.lastname: Elias
authors.affiliation: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Jo Fackler
authors.affiliation: Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Robert
authors.initials: R
authors.lastname: van Domselaar
authors.affiliation: Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Karijn P M
authors.initials: KP
authors.lastname: Suijkerbuijk
authors.affiliation: Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Arjen J
authors.initials: AJ
authors.lastname: Witkamp
authors.affiliation: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, USA.
authors.forename: Saraswati
authors.initials: S
authors.lastname: Sukumar
authors.affiliation: Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: van Diest
authors.affiliation: Department of Medical Oncology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Elsken
authors.initials: E
authors.lastname: van der Wall
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008875:Middle Aged; D055966:Nipple Aspirate Fluid / Q000737:chemistry*
chemical_list: D004273:DNA, Neoplasm
keywords: breast cancer; methylation; nipple fluid