Potential Benefits of Complementary Therapies for Women with Breast Cancer Undergoing Oncological Treatment: A Systematic Review

Background/Objectives: Breast cancer is the most prevalent malignancy among women worldwide and remains a major cause of morbidity and mortality. Conventional treatments, while effective, often produce physical and psychological adverse effects that impair quality of life. Complementary therapies (CTs) have gained prominence as supportive strategies to mitigate these effects. This systematic review aimed to evaluate the potential benefits of CTs in women with breast cancer undergoing or having completed chemotherapy and radiotherapy. Methods: Following PRISMA 2020 guidelines and Cochrane standards, a systematic search was conducted in PubMed, CINAHL, Web of Science, and Scopus for studies published up to March 2026. Randomized controlled trials assessing CTs in breast cancer patients were included. Methodological quality was appraised using the PEDro scale, and risk of bias was evaluated using the Cochrane RoB 2 tool. Results: Thirty-two RCTs met the inclusion criteria. The interventions included acupuncture and related techniques, mindfulness-based therapies, massage, dance–movement therapy, music therapy, slow breathing, prayer, and natural products. Overall, CTs produced improvements in pain, fatigue, anxiety, depression, sleep quality, and social well-being, though the effects were sometimes therapy-specific and varied. Conclusions: Complementary therapies represent non-pharmacological strategies that may offer potential benefits across physical, emotional, and social outcomes in women with breast cancer. However, mixed results in certain therapies indicate that conclusions must be drawn cautiously. Future research should pursue methodological consistency and longer follow-ups.