Effects of behavioral intervention on plasma cortisol and lymphocytes in breast cancer patients: An exploratory study

In order to evaluate the effects of a behavioral intervention on endocrine and immunological parameters, 24 breast cancer patients were investigated after standard surgical treatment of their tumors and without adjuvant tumor treatment. Of these, 14 patients were allocated to the intervention group and 10 patients served as controls. Interventions were conducted once a week over a period of 10 weeks. To determine short- and longer-term intervention effects on plasma concentration of cortisol and lymphocyte numbers, blood samples were taken before and after the second and 10th session. Psychological variables such as illness-related coping showed no changes within the intervention period (10 weeks). However, there were short- (pre- versus post sessions) and longer-term (9 weeks) reductions in plasma levels of cortisol in the intervention group. In parallel to the reduced plasma concentration of cortisol, a short-term increase of lymphocyte numbers after the second and the 10th session, as well as an increase over a period of nine weeks in the intervention group, was observed. This data indicate that behavioral intervention influences endocrine and immunological functions in breast cancer patients.