Revisiting Curcumin in Cancer Therapy: Recent Insights into Molecular Mechanisms, Nanoformulations, and Synergistic Combinations

Curcumin has been extensively investigated as an anticancer agent, yet its clinical application remains constrained by low bioavailability, incomplete mechanistic understanding, and limited therapeutic optimization. In light of growing resistance to conventional chemotherapies and the demand for safer, multi-targeted agents, this review revisits curcumin with a contemporary lens. We critically evaluate the literature published since 2020, focusing on newly elucidated molecular mechanisms by which curcumin regulates tumor progression, including modulation of oncogenic signaling pathways (Wnt/β-catenin, PI3K/Akt/mTOR, JAK/STAT, and MAPK), induction of ferroptosis, and epigenetic reprogramming. A particular emphasis is placed on recent advances in nanoformulation strategies that enhance curcumin’s pharmacokinetic profile and target-specific delivery. Furthermore, the emerging paradigm of combination therapy is explored, where curcumin acts synergistically with chemotherapeutics and phytochemicals to overcome drug resistance and potentiate anticancer efficacy. This review identifies key knowledge gaps, such as inconsistent clinical translation and the underexplored interplay between nanocurcumin systems and immune modulation, outlining directions for future translational research.