Effect of radiotherapy on cellular kinetics of peripheral blood monocytes in patients with malignant tumors

Objective To investigate the effect of radiotherapy on cellular kinetics of peripheral blood monocytes in patients with malignant tumors. Methods In patients with malignant tumors, apoptosis and proliferative activity of peripheral blood monocytes were monitored and compared before, during and after radiotherapy. Results Apoptosis and S phase fraction in cancer patients on radiotherapy were higher as compared to these without radiotherapy or the normal control group (8.93%±6.94%, 0.20%±0.20%, 0.15% ±0.13%, and 1.23%±1.15%, 0.54%±0.46%, and 0.33%±0.26%,respectively,F=5.77, P0.01 and F=3.18,P0.05). Apoptosis and S phase fraction of peripheral blood monocytes in patients 1 month after radiotherapy were higher than these of patients 1～3 months after radiotherapy (16.56%±12.95%,1.76%±1.75% and 0.49%±0.29%,0.50%±0.48%, respectively,t=9.06,P0.01 and t=4.61,P0.01). Conclusions Radiotherapy may induce the changes of cellular kinetics of peripheral blood monocytes in patients with malignant tumors. Apoptosis and S phase fraction were gradually increased with increase of time during the period of radiotherapy. The results provides new data to study radiation response in patients with malignant tumors.