Abstract
PURPOSE: Fatigue is a highly prevalent and disabling symptom for patients with metastatic breast cancer (MBC). Evidence-based interventions for managing fatigue in advanced cancer populations are lacking. This phase II randomized controlled trial tested the effect of acceptance and commitment therapy (ACT) on fatigue interference with functioning in patients with MBC. METHODS: Eligible patients were women with stage IV breast cancer who had moderate to severe fatigue interference. Patients completed a baseline assessment that included self-report measures of fatigue interference with activities, mood, and cognition (primary outcome) and sleep interference with functioning, engagement in daily activities, and quality of life (QOL; secondary outcomes). Then patients were randomly assigned to six weekly telephone-delivered sessions of either ACT (n = 116) or education/support (n = 120). Follow-up assessments occurred at 2 weeks, 3 months, and 6 months postintervention (means, 9.69, 20.51, and 33.59 weeks postbaseline, respectively). RESULTS: Linear mixed model analyses showed that compared with patients in the education/support condition, patients in the ACT condition reported significantly less fatigue interference (P = .018). These results were significant at 2 weeks and 6 months postintervention. ACT's effect on sleep interference was not statistically significant after the Sidak adjustment for multiple comparisons (P = .037). ACT patients showed a steady decline in sleep interference, a trend that was not found for education/support patients. Engagement in daily activities and QOL did not significantly differ between study groups, except for functional QOL (P = .006). Compared with education/support patients, ACT patients showed significantly better functional QOL at 2 weeks and 6 months postintervention. CONCLUSION: Results suggest that a brief, telephone-delivered ACT intervention can reduce fatigue interference with functioning in patients with MBC.