Effectiveness of a short-term group psychotherapy program on endocrine and immune function in breast cancer patients: An exploratory study

Cancer patients who had been treated for early stage breast cancer and were diagnosed with either positive axillary lymph nodes or distant metastases were randomly assigned to either a 13-week experiential-existential group psychotherapy (EEGP) program or a waiting list control (WLC) condition. Endocrine and immune measures were obtained before and after the intervention period. The findings of this study are that, after the 13 weeks of the experiment, patients in the EEGP group showed lower levels of plasma cortisol and lower levels of prolactin as well as lower percentages of natural killer cells, CD8 cells, and CD4 cells in addition to a lower proliferative response to pokeweed mitogen than patients in the WLC group. Importantly, this was only found in those breast cancer patients presenting relatively high endocrine and immune baseline levels, suggesting that the patients' profile with regard to endocrine and immune function at the start of a program can have an important effect. If replicated on a larger scale, the current results may be relevant for the treatment of breast cancer.