title: Elevated level of cell-free plasma DNA is associated with breast cancer.
abstract: BACKGROUND
  We analysed cell-free DNA (cfDNA) in the plasma of patients with both malignant and benign breast lesions by real-time quantitative PCR to determine whether the finding may have diagnostic and prognostic implications.
  
  
  METHODS
  Plasma samples were obtained from 33 patients with breast cancer, 32 patients with benign breast lesions and 50 healthy women as normal controls. Circulatory cfDNA was extracted from the plasma samples and quantified by real-time quantitative PCR for the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene.
  
  
  RESULTS
  The mean concentrations of cfDNA in the plasma samples from patients with breast cancer, patients with benign breast lesions and normal controls were 2,285, 1,368 and 1,489 genome equivalents (GE) per millilitre, respectively. The level of cfDNA in the breast cancer group was significantly higher than those in the benign lesion group and control group (P = 0.007 and 0.013, respectively). These findings were associated with malignant tumour size. The levels of the cfDNA were high in patients with lymph node involvement and distant metastasis.
  
  
  CONCLUSIONS
  Our results suggest that levels of cfDNA in the plasma are elevated in malignant breast cancer and correlated with tumour size. These findings could have diagnostic and prognostic value for malignant breast tumours.
authors: Laboratory for Prenatal Medicine and Gynaecological Oncology, Department of Obstetrics and Gynaecology, University of Basel, Basel, Switzerland. xzhong@uhbs.ch
authors: Xiao Yan
authors: XY
authors: Zhong
authors: Ariane
authors: A
authors: Ladewig
authors: Seraina
authors: S
authors: Schmid
authors: Edward
authors: E
authors: Wight
authors: Sinuhe
authors: S
authors: Hahn
authors: Wolfgang
authors: W
authors: Holzgreve
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D001941:Breast Diseases / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology; D002474:Cell-Free System; D015331:Cohort Studies; D004247:DNA / Q000097:blood* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D010949:Plasma / Q000737:chemistry; D016133:Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D004247:DNA