Comet assay, a possible screening assay to classify subgroups of individuals with different radiosensitivity using high throughput scanning system for multiple samples of human blood lymphocytes.

This research was designed to identify the correlation between clinical radiosensitivity among breast cancer patients and in vitro radiosensitivity measured by alkaline comet assay in high throughput fashion. In 68 patients with breast cancer, acute adverse effects on skin after radiotherapy were clinically scored. Among these patients, maximum score was grade 0 for 10 patients, grade 1 for 28 patients, grade 2 for 25 patients, and grade 3 for 5 patients. Correlation between initial damage and skin reaction was found in breast cancer patients with grade 1 and grade 2, 3 (p= 0.034). There was also correlation between residual damage (RD) and skin reaction in these two groups (p= 0.033). Large inter-individual variation of RD was also noticed among breast cancer patients with grade 0 (17.5+- 12.7 %), or grade 2, 3 (16.8+- 10.7 %). By introducing a new analyzer with a motorinzed scanning stage for 8 slides, throughput of the comet assay data was highly improved. There was no difference in any comet parameter between cancer patients and age-matched 41 healthy volunteers. Our data suggests that the comet assay might be one of supportive assays to classify subpopulation of patients who have different radiosensitivity from normal responders with a fair discriminating capacity.International Comet Assay Workshop No.