Immune responses to guided imagery during breast cancer treatment.

ABSTRACT

BACKGROUND: The use of relaxation and guided imagery to reduce stress and improve immune function has great potential benefits for patients with breast cancer. METHODS: This pilot study used a pretest-posttest experimental design with 28 breast cancer patients, aged 25 to 75 years, with the diagnosis of stage 0, 1, or 2 breast cancer. The experimental group received a relaxation and guided imagery intervention and the control group received standard care. The effects of the intervention on immune function were measured by natural killer (NK) cell cytotoxicity and IL-2-activated NK cell activity prior to surgery and 4 weeks postsurgery. NK cell activity was measured using a 15-hr incubation chromium release assay. Cytotoxicity of NK cells was measured against chromium-labeled K-562 target cells. IL-2 was used to enhance reactivity of NK cells against tumor cells. After incubation for 15 hr, cytotoxicity was measured through the release of radioactive chromium. RESULTS: Significant differences between groups were found at 4 weeks postsurgery. T-tests showed increased NK cell cytotoxicity for the intervention group at 1001, 501, and 251 effector cell target cell ratios (ET) (p < .01 to p < .05) and increased activation for IL-2 at 1001, 501, 251, and 12.51 (ET) (p < .01 to p < .05) for the intervention group as compared to the control group. DISCUSSION: These findings suggest that a relaxation intervention such as guided imagery could have an effect on NK cell cytotoxicity and NK cell cytotoxicity after activation with IL-2 in patients undergoing surgery for breast cancer.