Apoptotic activity in lymphocytes from radiation-treated cervical cancer patients

The per cent apoptotic activity in lymphocytes from pre-treated cervical cancer patients was cross-sectionally compared with post-treated patients at 1 month, 3 months, 1 year, and 5 years after completing the standard radiation therapeutic regimen. In addition, the differences in the per cent apoptotic activities among various stages of cervical cancer were simultaneously analyzed.

Blood samples were collected from five patients in each stage of cervical cancer before treatment, and at 1 month, 3 months, 1 year, and 5 years after completing the radiation therapy. The control samples were collected from healthy and aged-match female blood donors. The lymphocytes were separated and exposed to 0.5 Gy Co irradiation to induce apoptosis. The apoptotic cells were detected by in situ terminal deoxynucleotidyl transferase (TdT assay) and counted under a fluorescent microscope. Both the apoptotic index and per cent apoptotic activity were calculated.

The per cent apoptotic activities in lymphocytes from all pre-treated patients with stage II and III cervical cancer were significantly lower than the controls (p = 0.001). The apoptotic activity in normal control, however, was not significantly different from the pre-treated stage I cervical cancer group. Following radiation therapy, the apoptotic activities at 1 month, 3 month and 1 year were increased in all stages. The per cent apoptotic activity, in all stages of cervical cancer at 5 years after treatment, was statistically higher than that of the pre-treated groups.

There was a decrease of per cent apoptotic activity in lymphocytes from all pre-treated cervical cancer patients in the present study, the change of which was reversed to normal after treatment in non-recurrent cases.