Common fragile site expression and genetic predisposition to breast cancer

The expression of common fragile sites induced by aphidicolin and caffeine was evaluated on prometaphase obtained from the peripheral blood lymphocyte s of 35 women with breast cancer, their 35 clinically healthy female family members, and 20 sex- and age-matched normal controls. As a result of the c ytogenetic and statistical evaluation, the number of damaged cells, chromos omal aberrations, and expression frequencies of fragile sites detected in p atients with breast cancer and their first-degree relatives were found to b e significantly higher than those in the control group. Our findings indica te an increased genetic instability in women with breast carcinomas and the ir relatives. Therefore, fragile sites may be used as a reliable marker for defining genetic susceptibility to cancer in general. (C) 1998 Wiley-Liss, Inc.