Spontaneous chromosomal instability in breast cancer families

Spontaneous chromosomal instability has been correlated with cancer predisp osition. In the present study, the phenomenon has been evaluated using two cytogenetic markers, namely, frequency of spontaneous sister chromatid exch anges (SCE) and spontaneous chromosomal aberrations (CA) in peripheral bloo d lymphocytes of hereditary breast cancer (HBC) patients (n = 11) and healt hy blood relatives (HBR, n = 36). A statistically significant difference wa s observed for both the endpoints en between HBC patients and controls (P < 0.001), HBC patients and HBR (P < 0.001), as well as HBR and controls (P < 0.001). Thus, 63.64% of the HBC patients and 25% of HBR showed a mean CA/c ell value higher than the highest mean CA/cell value of the controls (0.11 CA/cell). Similarly, 81.81% of the HBC patients and 61.11%;, of HER showed a mean SCE/cell value higher than the highest mean SCE/cell value of the co ntrols (9.60 SCE/cell). Chromosomal aberrations il ere more frequently obse rved in the B and E group of chromosomes in HBC patients and HBR. These fin dings primarily indicate the high level of chromosomal instability in breas t cancer families, and might be one of the predisposing factors for hi,oh r isk of cancer in HBR. (C) Elsevier Science Inc., 2000. AII rights reserved.