Curcumin and Tamoxifen in Breast Cancer Therapy: A Scoping review

Tamoxifen (TMX) is a widely used first-line hormonal therapy for breast cancer; however, prolonged use is associated with hepatic toxicity and endocrine resistance, potentially compromising treatment outcomes. Curcumin (CUR) has been investigated as a potential adjuvant to TMX therapy. This scoping review aimed to map the existing scientific evidence on the effects of CUR co-administration with TMX in breast cancer treatment. The review followed PRISMA-ScR guidelines and searched six databases (PubMed, Scopus, Web of Science, Embase, Cochrane Library, and Google Scholar) for studies published between 2005 and 2025. In vitro, in vivo, and clinical studies evaluating CUR and TMX co-administration were included. Of 1,343 records identified, 14 studies met the inclusion criteria: 11 in vitro, two clinical trials, and one combined in vivo/in vitro study. Most preclinical studies reported synergistic effects under experimental conditions. Although several preclinical studies reported synergistic effects under experimental conditions, the available clinical evidence remains limited and inconsistent.