Mindfulness-Based Cognitive Therapy for Psychological Distress, Fear of Cancer Recurrence, Fatigue, Spiritual Well-Being, and Quality of Life in Patients With Breast Cancer—A Randomized Controlled Trial

Context: Mindfulness-based interventions have been receiving growing attention in cancer care. Objectives: The purpose of this randomized controlled trial is to examine the effectiveness of mindfulness-based cognitive therapy (MBCT) for psychological distress (anxiety and depression), fear of cancer recurrence (FCR), fatigue, spiritual well-being, and quality of life (QOL) in Japanese ambulatory patients with Stage I–III breast cancer. Methods: A total of 74 patients were randomly assigned to either an eight-week MBCT intervention group (n = 38) or a wait-list control group (n = 36). The primary outcome was psychological distress, measured on Hospital Anxiety and Depression Scale. The secondary outcomes were FCR (Concerns About Recurrence Scale—overall anxiety subscale), fatigue (Brief Fatigue Inventory), spiritual well-being (Functional Assessment of Chronic Illness Therapy—Spiritual), QOL (Functional Assessment of Cancer Therapy—General), and mindfulness skills (Five Facet Mindfulness Questionnaire). The participants were assessed at baseline (T0), Week 8 (T1), and Week 12 (T2). The results were analyzed using a intention-to-treat linear mixed model. Results: The participants in the MBCT group experienced significantly better outcomes in their psychological distress (Cohen's d = 1.17; P < 0.001), FCR (d = 0.43; P < 0.05), fatigue (d = 0.66; P < 0.01), spiritual well-being (d = 0.98; P < 0.001), and QOL (d = 0.79; P < 0.001) compared with the control group. The difference remained significant at T2 (four weeks after completion of the intervention). Conclusion: MBCT was demonstrated to improve well-being that encompasses psychological, physical, and spiritual domains in Japanese patients with nonmetastatic breast cancer. The favorable effect was maintained up to four weeks after the completion of the intervention.