Abstract: Matched on a series of demographic and medical treatment variables, forty hospitalized breast cancer patients undergoing radiotherapy were randomly assigned to either a psycho-behavioral intervention group or a control group. The 4-week intervention primarily consisted of multiple sessions of muscle relaxation exercises and guided imagery treatment. The results showed that the level of NK cell activity of the intervention group was significantly higher than that of the control group. The number of patients in the intervention group who had to use medicines to increase white blood cells during radiotherapy was significantly fewer than that of the control groups. No significant differences were found between these two groups in a set of emotional adjustment questionnaires. These results suggest that the intervention helped in strengthening patients' immune functioning but not in changing their emotional state..

Key words: breast cancer, psycho-behavioral intervention, emotional reaction to cancer, immune function