Impact of Active Iyengar Yoga Practice on Markers of Cell-mediated Cytotoxicity in Breast Cancer Survivors

Abstract

PURPOSE: To determine if an eight-week yoga practice improved markers of cell-mediated cytotoxicity in female breast cancer survivors. METHODS: Survivors (Stages I-IV, age 61 ± 7.4 yrs.) were randomly assigned to yoga (Y, n=10) or waitlisted (WL, n=9) groups. Demands of Illness (DOI) and immune indices were evaluated pre- (T1) and post-yoga (T2). Iyengar yoga practice occurred twice weekly, 90-minute per day plus one home practice. Data were analyzed by Mann-Whitney U test. RESULTS: The %CD16+CD56+ cells, %CD16brightCD56dim cells, and cytotoxicity against human leukemia cells (K562) were not altered from T1 to T2. Cytotoxicity against human breast cancer cells (MCF-7) decreased in WL (39.0±21.4 at T1 vs 19.1±17.2, LU per 107 effectors) but remained stable in Y (30.3±19.6 at T1 vs 31.2±17.7, LU per 107 effectors), such that at T2, Y had a significantly greater cytolytic response (p<0.05). DOI for treatment, exercise and diet significantly declined from T1 to T2 with yoga. CONCLUSION: Yoga participation was associated with greater stability in cell-mediated cytotoxicity against a tumor target that is biologically relevant to the clinical diagnosis of breast cancer.