title: Identification of biomarkers for breast cancer in nipple aspiration and ductal lavage fluid.
abstract: OBJECTIVE
  To establish a comprehensive proteomic approach for biomarker discovery and validation in breast fluid.
  
  
  METHODS
  A total of 95 specimens from three institutions were used including 10 nipple aspiration fluid (5 stage I/II cancerous breasts and 5 age-matched healthy controls), 42 ductal lavage fluid from 14 patients with unilateral stage I/II cancer (25 from 9 cancerous breasts and 17 from 7 contralateral breasts), and 42 ductal lavage fluid from 14 high-risk women (multiple ducts repeated lavage). Differentially expressed protein/peptides were discovered by proteomic analysis of training sample, using ProteinChip arrays and surface-enhanced laser desorption ionization (SELDI) time-of-flight mass spectrometry, and validated on independently collected testing samples. After protein identification, ELISA was done to confirm the SELDI findings.
  
  
  RESULTS
  We were able to obtain reproducible protein profiles using minimal amount of protein (1 mug) by applying an optimized chip protocol and SELDI. We were able to select cancer-associated biomarkers despite large individual variability by applying both unsupervised and supervised cluster analysis. Furthermore, we were able to train and test candidate biomarkers on independently collected samples and identified one component of a multimarker panel as human neutrophil peptides 1 to 3.
  
  
  CONCLUSIONS
  Breast fluid is a rich source of breast cancer biomarkers. In combination with high-throughput novel proteomic profiling technology and multicenter study design, markers that are highly specific to breast cancer can be discovered and validated. Our observations also suggest that persistent elevation of human neutrophil peptide in high-risk women may imply early onset of cancer not yet detectable by current detection method. Proof of this hypothesis requires follow-up on a larger study population.
authors.affiliation: Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA. jli@jhmi.edu
authors.forename: Jinong
authors.initials: J
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yu
authors.forename: Julie
authors.initials: J
authors.lastname: Lange
authors.forename: Henry
authors.initials: H
authors.lastname: Kuerer
authors.forename: Savitri
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Eric
authors.initials: E
authors.lastname: Schilling
authors.forename: Seema A
authors.initials: SA
authors.lastname: Khan
authors.forename: Saraswati
authors.initials: S
authors.lastname: Sukumar
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Chan
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis*; D044963:Biopsy, Fine-Needle; D001826:Body Fluids / Q000737:chemistry*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology; D044584:Carcinoma, Ductal / Q000737:chemistry / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D009363:Neoplasm Proteins / Q000032:analysis*; D009558:Nipples / Q000378:metabolism*; D040081:Protein Array Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D007507:Therapeutic Irrigation
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins