Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 17 2 2026 08 09 241 251 Arman Ryahin Department of Community Health Nursing, Faculty of Nursing And Midwifery, Kurdistan University of Medical Science, Sanandaj, Iran Kaveh Ebadi Department of Medical-Surgical Nursing, Faculty of Nursing And Midwifery, Kurdistan University of Medical Science, Sanandaj, Iran Farhad Azadmehr Department of Medical-Surgical Nursing, Clinical Care Research Center, Research Institute for Health Development, Kurdistan university of Medical Science, Sanandaj-Iran 2025 11 02 2026 01 30 Introduction:Breast cancer is the most common invasive cancer among women worldwide. While advancements in early diagnosis and treatment have improved survival rates, many breast cancer patients experience persistent sleep disturbances, anxiety, and stress, which negatively impact their quality of life. Pharmacological treatments for sleep disorders pose risks such as dependency and side effects, making non-pharmacological interventions like mindfulness-based interventions (MBIs) increasingly relevant. This systematic review evaluates the effectiveness of MBIs, particularly Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT), in improving sleep quality and reducing psychological distress in breast cancer patients. Methods:Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted across databases including PubMed, Web of Science (WOS), Scopus, Cochrane Library, SID, Irandoc, and Noormags. Studies published up to November 5, 2024, were screened using Medical Subject Headings (MeSH) terms and Boolean operators. Eligible studies included randomized controlled trials (RCTs) and quasi-experimental studies investigating MBIs' effects on sleep and psychological health in breast cancer patients. Data extraction and quality assessment were performed using the Joanna Briggs Institute (JBI) checklist. Results:Out of 207 initially identified studies, eight met the inclusion criteria. MBIs significantly improved sleep quality by reducing insomnia severity, sleep latency, and nighttime awakenings while enhancing sleep efficiency. Additionally, MBIs led to substantial reductions in anxiety and depression scores. Some studies reported improvements in emotional resilience and psychological well-being. However, variations in intervention duration, follow-up periods, and study designs influenced result consistency. Discussion:The findings indicate that MBIs effectively enhance sleep quality and reduce psychological distress in breast cancer patients. Compared to pharmacological treatments, MBIs provide a safer, non-invasive alternative. The benefits are attributed to mindfulness-induced stress reduction and emotional regulation. Despite promising outcomes, variations in methodologies and limited long-term evaluations warrant further research. Conclusion:MBIs are a valuable complementary approach to conventional breast cancer care, addressing sleep and psychological challenges. Further large-scale, high-quality RCTs are needed to confirm long-term efficacy and establish standardized protocols. https://bccr.tums.ac.ir/index.php/bccrj/article/view/586