Effect of long term yoga practice on psychological and immune outcomes in breast cancer survivors

Abstract

Background: Breast cancer has become a global pandemic with an increasing incidence. Better diagnostic tools and treatment modalities have reduced mortality considerably resulting in a large number of survivors who face several cancer and treatment related long term symptoms. Lifestyle interventions like yoga are becoming more acceptable with many survivors taking it up for improving Quality of life. The present study attempted to evaluate the psychological and immune effects of long term yoga practice in breast cancer survivors. Methods: A cross sectional study recruited female breast cancer survivors (stage II or III, IDC or ILC), between the ages of 30-65 years, having completed cancer treatment more than six months prior to recruitment from three cancer hospitals in Bengaluru, India and grouped based on prior yoga experience [Breast Cancer Yoga (BCY, n = 27) or Naïve (BCN, n = 25)]. An extensive history was collected including demography, cancer history, diet, exercise habits, and yoga schedule. Psychometric tools to assess stress, anxiety, depression, general health and quality of life were administered. Blood samples were collected to evaluate cytokines from serum and NF-κB from peripheral blood mono-nucleated cells. Between group differences were evaluated by independent samples t-test or Mann Whitney-U test based on data distribution. Findings: Yoga group had significantly lower NF-κB (p = 0.016) and MCP-1 (p = 0.002) when compared to the non-yoga group. Other pro-inflammatory cytokines like IL-1β, IL-6, and IL-8 also showed a trend of lower values although not significant. Psychological variables showed significantly (p < 0.001) lower stress, anxiety, depression, and better general health and quality of life in the yoga group. Interpretations: The results indicate that breast cancer survivors doing yoga have better psychological profiles and lower levels of pro-inflammatory markers. This provides support to the psycho-oncogenic model of cancer etiology and indicates that yoga and lifestyle modification may have the potential to improve psychological and immune profiles thereby improve prognosis and survival outcomes in breast cancer.