Breathing Exercise for Chronic Pain Management in Breast Cancer Survivors: Feasibility Outcomes and Qualitative Insights from a Pilot Randomised Controlled Trial

<b>Background:</b> Feasibility studies enable the refinement of complex interventions and procedures prior to definitive trials. To establish robust evidence for clinical applications, this study evaluated the feasibility, acceptability and safety of an evidence-based breathing exercise (BE) intervention protocol among breast cancer survivors experiencing chronic pain. <b>Methods:</b> In an open-label pilot randomised controlled trial with a nested qualitative evaluation, 72 women were randomised into a BE plus routine care group (<i>n</i> = 36) or a routine care alone group (<i>n</i> = 36). Feasibility and acceptability outcomes included recruitment, retention, instrument completeness and suitability, intervention adherence, safety, and participants' perceived experience of practicing BE and participating in this study. Outcome assessments occurred at baseline (week 0), post-intervention (week 5), and follow-up (week 9). Quantitative data were analysed descriptively. Qualitative interviews (<i>n</i> = 20) explored participant experiences, and the data were analysed thematically. <b>Results:</b> The feasibility was high, with an 84% recruitment (72/86) and 94% retention (68/72), and the recruitment process took 19 weeks. The overall BE intervention adherence was 82.4%. Questionnaire completion was satisfactory, with minimal missing values reported in the questionnaire. No serious adverse events occurred. Evidence from qualitative evaluation reinforced the feasibility from quantitative data. <b>Conclusions:</b> The BE protocol and study procedures were feasible, acceptable, and safe in this population. A fully powered RCT is warranted to determine the effectiveness and durability of the outcomes.