In spite of great progress in therapeutic practices over the past decade, neither the incidence nor the deaths from cancer have changed over the past thirty years. Existing anticancer drugs have limited efficacy, severe complications, and high costs expensive. Hence, identifying pharmaceutical agents lacking these disadvantages is required. Curcumin (diferuloylmethane), bioactive phenolic component of turmeric derived from the curcuma longa linn rhizome, is such a factor that over the past three to four decades extensive in vitro and in vivo studies have shown it to have anti-cancer, antiviral, anti amyloid, antioxidant, and anti-inflammatory properties. The underlying mechanisms of these effects are various and seem to include different molecular targets, such as transcription factors, growth factors, inflammatory cytokines, protein kinases, enzymes, and the like. This paper reviews modulated molecular-targets of curcumin and its signaling paths. Moreover, in the status quo, a number of curcumin nano-formulations and its use in cancer treatment were discussed.