Expression of aphidicolin-induced fragile sites in lymphocytes of patients with breast cancer.

The expression of fragile sites induced by aphidicolin (APC) was evaluated on metaphase chromosomes obtained from the peripheral blood lymphocytes of 26 women with breast cancer and 15 sex- and age-matched normal controls. Both the proportion of damaged cells (P < 0.001) and the mean number of gaps and breaks per cell (0.02 < P < 0.05) were significantly higher in the patient group. There were no differences in either the age-related fragile site levels or the expression of single fragile sites between patients and controls. Our findings indicate an increased genetic instability in women with breast carcinoma.