Abstract
Breast cancer remains a leading cause of morbidity and mortality among women globally, with increasing incidence projected in the coming years. Despite advances in standard oncologic therapies, there is a growing interest in supportive interventions that enhance treatment efficacy and reduce adverse effects. This review critically evaluates preclinical and clinical data on the medicinal mushroom Coriolus versicolor and its bioactive compounds-primarily polysaccharide-K, polysaccharopeptide, and laccase-as potential adjuvants in breast cancer therapy. A systematic PubMed search identified 11 original studies from 2010 to 2025 examining the impact of C. versicolor on breast cancer cell lines, animal models, and human subjects. Findings consistently demonstrate antiproliferative, pro-apoptotic, necroptotic, anti-invasive, and immunomodulatory effects across various breast cancer subtypes, including triple-negative breast cancer. One phase I clinical trial also reported good tolerability and immunological benefits in patients post-chemotherapy. The review highlights molecular mechanisms involving apoptosis, necroptosis, and modulation of the tumor microenvironment. While promising, these results underscore the need for standardized preparations, pharmacokinetic data, and larger placebo-controlled trials. Overall, C. versicolor shows potential as a safe, natural adjunct to conventional therapy, offering prospects for integrative strategies in breast cancer management.