title: DNA double-strand breaks induced by mammographic screening procedures in human mammary epithelial cells.
abstract: OBJECTIVE
  To assess in vitro mammographic radiation-induced DNA damage in mammary epithelial cells from 30 patients with low (LR) or high (HR) family risk of breast cancer.
  
  
  METHODS
  Spontaneous and radiation-induced DNA double-strand breaks (DSB) were quantified by using immunofluorescence of the phosphorylated H2AX histone (γH2AX) in different conditions of mammography irradiation (2, 4, 2 + 2 mGy).
  
  
  RESULTS
  HR patients showed significantly more spontaneous γH2AX foci than LR patients (p = 0.014). A significant dose-effect was observed, with an exacerbation in HR patients (p = 0.01). The dose repetition (2 + 2 mGy) provided more induced and more unrepaired DSB than 2 mGy and 4 mGy, and was exacerbated in HR (p = 0.006).
  
  
  CONCLUSIONS
  This study highlights the existence of DSB induced by mammography and revealed by γH2AX assay with two major radiobiological effects occurring: A low-dose effect, and a LOw and Repeated Dose (LORD) effect. All these effects were exacerbated in HR patients. These findings may lead us to re-evaluate the number of views performed in screening using a single view (oblique) in women whose mammographic benefit has not properly been proved such as HR patients.
authors.affiliation: Hospices Civils de Lyon, Service de Radiologie, Centre Hospitalier Lyon Sud, Pierre-Bénite, France. catherine.colin3@orange.fr
authors.forename: Catherine
authors.initials: C
authors.lastname: Colin
authors.forename: Clément
authors.initials: C
authors.lastname: Devic
authors.forename: Alain
authors.initials: A
authors.lastname: Noël
authors.forename: Muriel
authors.initials: M
authors.lastname: Rabilloud
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Zabot
authors.forename: Sylvie
authors.initials: S
authors.lastname: Pinet-Isaac
authors.forename: Sophie
authors.initials: S
authors.lastname: Giraud
authors.forename: Benjamin
authors.initials: B
authors.lastname: Riche
authors.forename: Pierre-Jean
authors.initials: PJ
authors.lastname: Valette
authors.forename: Claire
authors.initials: C
authors.lastname: Rodriguez-Lafrasse
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foray
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001940:Breast / Q000528:radiation effects*; D053903:DNA Breaks, Double-Stranded; D004847:Epithelial Cells / Q000528:radiation effects; D005260:Female; D006657:Histones / Q000032:analysis; D006801:Humans; D008327:Mammography / Q000009:adverse effects*; D048629:Micronuclei, Chromosome-Defective; D008875:Middle Aged
chemical_list: C468783:H2AX protein, human; D006657:Histones