title: Familial breast cancer. Part III: Genome instability and cancer risk.
abstract: OBJECTIVE
  The purpose of part III of this study was to direct our efforts towards more detailed genetic studies, which can be used in genetic counselling of patients with breast cancer and their relatives.
  
  
  METHODS
  We investigated 52 patients, 25 with chromosomal fragility and 17 with spontaneous chromosomal aberrations, all with familial breast cancer (study group). The control group consisted of 10 healthy women without a history of proliferative diseases or breast cancer in their families. The chromosomal fragility and spontaneous chromosomal aberrations were studied in peripheral blood lymphocytes cultured for 72 and 48 hours, respectively, at 37 degrees C, following a standard procedure.
  
  
  RESULTS
  In the patients with breast cancer the expression of chromosomal fragility was significantly higher (19.47%) compared to 11.61% in the control group (p<0.0001). In the patients with familial breast cancer the spontaneous chromosomal aberrations were significantly higher (6.72%) compared with those of the normal individuals (1.98%, p<0.0001). In the study group spontaneous breaks in a single lymphocyte were 0.15, while they were 0.05 in the control group (p<0.0001).
  
  
  CONCLUSIONS
  The values of chromosomal fragility and chromosomal aberrations have some practical and theoretical importance in genetic services. The different variants in genomic stability are related with individual breast cancer development risk. Our results support the idea that the fragile sites and chromosomal aberrations may act as predisposing factors in carcinogenesis.
authors.affiliation: Department of Medical Genetics, Medical University, Sofia, Bulgaria.
authors.forename: M
authors.initials: M
authors.lastname: Nacheva
authors.forename: I
authors.initials: I
authors.lastname: Gavrilov
authors.forename: D
authors.initials: D
authors.lastname: Tzingilev