Effects of radiotherapy and chemotherapy on sister chromatid exchanges in peripheral lymphocytes of the patients with gynecologic cancer.

Studies were done on the influence of radiotherapy or chemotherapy on peripheral lymphocyte SCE (sister chromatid exchange) frequency in patients with gynecologic cancer. The average value of spontaneous SCE frequency in 10 patients who had received radiotherapy was 6.94 +/- 2.57 (mean +/- S.D.), which was significantly lower than the control value of 8.59 +/- 2.99 ( p less than 0.001). The rate of decline of these frequency values was negatively correlated with the irradiation dosage. In contrast, the average spontaneous SCE frequency in the patients who had received combination chemotherapy was 12.48 +/- 4.02, which was significantly higher than the control value ( p less than 0.001). The average value of MMC-induced SCE frequency in patients under chemotherapy was much the same as the control value of 26.16 +/- 5.77. That is patients under radiotherapy was 23.88 +/- 5.65, which was slightly lower than the control value. There was, however, no significant difference in the MMC-induced SCE frequency value among these 3 groups.