RESUMEN
Sister chromatid exchanges [SCEs] can be induced by various genotoxic treatments, suggesting that SCEs reflect a DNA repair process and it may be a good index for assessment of genomic instability. However, the occurrence of genetic instability and in particular, of spontaneous SCEs has been strongly linked to cancer. Several chromosomal regions and many genes have been implicated in breast cancer. Blood samples were obtained from 31 Iranian breast cancer patients and 11 healthy women. SCE was measured in peripheral blood lymphocytes by adding to Ham'sF10 medium in presence of PHA, BrdU [5-bromo-deoxy Uridine] fluorochrome Hoechst 33258, exposure to UV light and Giemsa staining. Then, SCE frequencies of patient and control groups were compared by the Mann-Withney U-test. Significantly difference was observed between two groups [p < 0.001]. This study indicates that SCE can be used as a risk biomarker for breast cancer