Tai Chi Qigong for survivors of breast cancer: a randomised controlled trial

Abstract

BackgroundBreast cancer is the most common malignancy in Chinese women. Conventional cancer treatments can increase the survival but often cause cardiovascular complications that compromise quality of life. Findings from previous exploratory studies showed that Tai Chi Qigong (TCQ) might induce favourable cardiovascular changes in cancer survivors. We aimed to assess the efficacy of a TCQ programme in improving arterial haemodynamics and quality of life in breast cancer survivors. MethodsIn this single-blinded, randomised controlled trial, 54 Chinese women who survived breast cancer and completed conventional medical care were recruited through a cancer self-help group and a medical clinic in Hong Kong. The participants were randomly allocated to either TCQ or no training (control) using computer-generated random numbers. Participants in the TCQ group attended two 1 h sessions per week for 3 months at the Nature Health Qigong Association (Hong Kong); during these sessions participants practiced the 18 forms of Tai Chi Internal Qigong. Both groups received usual medical care. The primary outcomes were maximum systolic and minimum diastolic arterial blood flow velocities as measured by a Doppler ultrasound machine. The secondary outcomes were oxygen saturation in blood at rest (as measured by an oximeter) and quality of life measured with the Functional Assessment of Cancer Therapy–Breast (FACT-B v4). Data were collected at baseline, post-test, and 3 months (follow-up). Two-way repeated-measures analysis of variance and intention-to-treat analysis were used in data analysis. Ethical approval was obtained from the Human Research Ethics Committee of Hong Kong University. The trial was registered with ClinicalTrials.gov (NCT02420249). Written informed consent was obtained from each participant. FindingsBaseline characteristics were comparable between participants in the TCQ (n=33; mean age 52·7 years, SD 7·5 years) and control group (n=21; mean age 51·5 years, SD 8·2 years). The TCQ and control groups showed similar changes in systolic velocity (group-by-time interaction F2,102=2·118, 95% CI 14·90–18·13; p=0·126; ηp2=0·040) and diastolic velocity (group-by-time interaction2,102=1·375, 95% CI 1·49–2·33; p=0·258; ηp2=0·026). Blood oxygen saturation increased by 0·5% from baseline to follow-up test in the TCQ group (p=0·002, 95% CI −0·78 to −0·19) while no change was noted in the control group (p=0·119, 95%CI −1·03 to 0·13). The FACT-B total score decreased by 23·04 points (24·0%) between baseline and follow up in the control group only (p=0·033, 95% CI 2·12–43·97; TCQ group: p=0·427, 95%CI −8·33 to 19·22). No adverse events were reported. InterpretationThe TCQ programme improved blood oxygenation and quality of life, but it did not improve blood flow velocities in Chinese women who had survived breast cancer. Further studies could examine the mechanisms or causes of the favourable changes. FundingSeed Funding Programme for Basic Research (201410159001), the University of Hong Kong.