Curcumin as a complementary treatment in oncological therapy: a systematic review

Abstract

Purpose Curcumin, the active ingredient in turmeric, is employed by numerous cancer patients to support conventional cancer therapy. This systematic review aims to summarize the existing clinical evidence and to provide an overview of the potential benefits and risks associated with curcumin supplementation. Methods In January 2024, we conducted a systematic search of five electronic databases (Embase, Cochrane, PsycInfo, CINAHL, and Medline) using a complex search strategy. We included randomized controlled trials on the use, effectiveness, and potential harm of additional curcumin therapy in adult patients under cancer treatment. The risk of bias was assessed using Cochrane revised Risk of Bias Tool 2.0. Results This systematic review included 34 randomized controlled trials involving 2580 patients out of 11143 search results. Included patients were primarily diagnosed with head and neck cancer, followed by breast, prostate, and colorectal cancer. Therapy concepts encompassed topical or systemic curcumin administration. The studies reported heterogeneous results concerning oral and skin symptoms, pain, weight alteration and changes in body composition, survival, and disease progression. Significant findings were reported for oral mucositis and weight loss. Considering risk of bias, all studies had moderate to high risk of bias. Regarding side effects, one study reported significantly more vomiting in the curcumin group. Conclusion Although the results suggest promise in reducing mucositis and weight loss, a clear statement regarding the effectiveness of curcumin therapy on cancer patients cannot be made due to heterogeneous results and methodological limitations of the involved studies. Further investigations of higher quality are necessary to derive a definite recommendation for action.