Chromosomal radiosensitivity in breast cancer patients : influence of age of onset of the disease

The age dependency of onset of the disease on chromosomal radiosensitivity of an unselected group of breast cancer patients (n= 100) was investigated and compared to a group of healthy women (n=100). The chromosomal radiosensitivity was assessed with the G2 and the GO micronucleus (MN) assay. For the G2 assay lymphocytes were irradiated in vitro with a dose of 0.4 Gy (CO)-C-60 gamma-rays after 70 h incubation and chromatid breaks were scored in 50 metaphases. For the GO MN assay lymphocytes were exposed in vitro to 3.5 Gy (CO)-C-60-gamma-rays at low dose rate (LDR). 72 h post-irradiation cultures were arrested and micronuclei were scored in 1000 binucleate cells. The results demonstrated that the group of breast cancer patients was more radiosensitive than a population of healthy women and this with both the G2 and the GO MN assay. Analyses of the G2 and MN response in different age groups of the breast cancer patients revealed no significant differences in mean G2 and MN scores and suggest that the age of onset of the disease has no effect on chromosomal radiosensitivity in unselected breast cancer patients. Correlations with different clinical parameters were also investigated