title: Gene expression profiling of peripheral blood cells for early detection of breast cancer.
abstract: BACKGROUND
  Early detection of breast cancer is key to successful treatment and patient survival. We have previously reported the potential use of gene expression profiling of peripheral blood cells for early detection of breast cancer. The aim of the present study was to refine these findings using a larger sample size and a commercially available microarray platform.
  
  
  METHODS
  Blood samples were collected from 121 females referred for diagnostic mammography following an initial suspicious screening mammogram. Diagnostic work-up revealed that 67 of these women had breast cancer while 54 had no malignant disease. Additionally, nine samples from six healthy female controls were included. Gene expression analyses were conducted using high density oligonucleotide microarrays. Partial Least Squares Regression (PLSR) was used for model building while a leave-one-out (LOO) double cross validation approach was used to identify predictors and estimate their prediction efficiency.
  
  
  RESULTS
  A set of 738 probes that discriminated breast cancer and non-breast cancer samples was identified. By cross validation we achieved an estimated prediction accuracy of 79.5% with a sensitivity of 80.6% and a specificity of 78.3%. The genes deregulated in blood of breast cancer patients are related to functional processes such as defense response, translation, and various metabolic processes, such as lipid- and steroid metabolism.
  
  
  CONCLUSIONS
  We have identified a gene signature in whole blood that classifies breast cancer patients and healthy women with good accuracy supporting our previous findings.
authors.affiliation: Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Montebello, Oslo, NO-0310, Norway.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Aarøe
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Lindahl
authors.forename: Vanessa
authors.initials: V
authors.lastname: Dumeaux
authors.forename: Solve
authors.initials: S
authors.lastname: Saebø
authors.forename: Derek
authors.initials: D
authors.lastname: Tobin
authors.forename: Nina
authors.initials: N
authors.lastname: Hagen
authors.forename: Per
authors.initials: P
authors.lastname: Skaane
authors.forename: Anders
authors.initials: A
authors.lastname: Lönneborg
authors.forename: Praveen
authors.initials: P
authors.lastname: Sharma
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Børresen-Dale
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001773:Blood Cells / Q000378:metabolism*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged