title: A correlation between residual radiation-induced DNA double-strand breaks in cultured fibroblasts and late radiotherapy reactions in breast cancer patients.
abstract: OBJECTIVE
  Prediction of late normal tissue reactions to radiotherapy would permit tailoring of dosage to each patient. Measurement of residual DNA double strand breaks using pulsed field gel electrophoresis (PFGE) shows promise in this field. The aim of this study was to test the predictive potential of PFGE in a group of retrospectively studied breast cancer patients.
  
  
  METHODS
  Thirty nine patients, treated uniformly for breast cancer 9-15 years previously, with excision of the tumour and radiotherapy to the breast and drainage areas, were assessed clinically using the LENT SOMA scale, and a 5-mm punch biopsy taken from the buttock. Fibroblast cell strains were established and used to study residual DNA double strand breaks, using PFGE.
  
  
  RESULTS
  There were significant correlations between the DNA assay results and the fibrosis score (r(s) = 0.46; P = 0.003), the combined fibrosis and retraction score (r(s) = 0.45, P = 0.004) and the overall LENT score (r(s) = 0.43; P = 0.006). Using polychotomous logistic regression, the fibroblast DNA assay result was an independent prognostic factor for fibrosis severity.
  
  
  CONCLUSIONS
  There is a relationship between residual radiation-induced DNA damage in fibroblasts and the severity of the late normal tissue damage seen in the patients from whom the cells were cultured.
authors.affiliation: CRC Section of Genome Damage and Repair, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Kiltie
authors.forename: A J
authors.initials: AJ
authors.lastname: Ryan
authors.forename: R
authors.initials: R
authors.lastname: Swindell
authors.forename: J B
authors.initials: JB
authors.lastname: Barber
authors.forename: C M
authors.initials: CM
authors.lastname: West
authors.forename: B
authors.initials: B
authors.lastname: Magee
authors.forename: J H
authors.initials: JH
authors.lastname: Hendry
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D016521:Electrophoresis, Gel, Pulsed-Field; D005347:Fibroblasts / Q000648:ultrastructure*; D005355:Fibrosis; D006801:Humans; D011832:Radiation Injuries / Q000473:pathology*; D011878:Radiotherapy / Q000009:adverse effects; D012189:Retrospective Studies
chemical_list: D004247:DNA