An evidence-based breathing exercise intervention for chronic pain management in breast cancer survivors: A phase II randomized controlled trial

Objective: Explore the preliminary effects of a breathing exercise (BE) intervention on chronic pain among breast cancer survivors. Methods: This two-parallel-arm, open-label pilot randomized controlled trial recruited 72 breast cancer survivors who were randomly allocated to either the control or intervention group (n = 36 each). Both groups received usual care and a pain information booklet, while the intervention group received 4 weeks of additional BE. The primary clinical outcome was measured using the Brief Pain Inventory (BPI), with secondary clinical outcomes measured by the Hospital Anxiety and Depression Scale (HADS), Quality of Life Patient/Cancer Survivor Version in Chinese (QOLCSV-C), and Functional Assessment of Cancer Therapy- Breast (FACT-B) immediately post-intervention and at 4-week follow-up. Both adjusted and unadjusted Generalized Estimating Equation models were utilized to assess the BE's potential effects, with safety assessed through participant self-report. Results: Sixty-eight participants completed the study. Statistical significance was observed in BPI in both adjusted and unadjusted models at post-intervention and follow-up (p < 0.05). BE demonstrated positive effects on anxiety, depression and quality of life improvement across all measures and timepoints in both adjusted and unadjusted models (p < 0.05). The effect sizes were smaller in the adjusted model. Three mild transient discomforts were reported associated with BE practice including dizziness, tiredness and yawning, without requirement of medical treatment. No severe adverse events occurred. Conclusion: This BE intervention appears effective in alleviating chronic pain, anxiety and depression, and improving quality of life for breast cancer survivors. Fully powered large-scale studies are required to confirm its effects.