Review on nanomedicine and phytotherapy for cancer

Cancer is well recognized as a leading cause of mortality. Although surgery tends to be the primary treatment option for many solid cancers, cancer surgery is still a risk factor for metastatic diseases and recurrence. For this reason, a variety of medications has been adopted for the postsurgical care of patients with cancer. However, conventional medicines have shown major challenges such as drug resistance, a high level of drug toxicity, and different drug responses, due to tumor heterogeneity. Nanotechnology-based therapeutic formulations could effectively overcome the challenges faced by conventional treatment methods. In particular, the combined use of nanomedicine with natural phytochemicals can enhance tumor targeting and increase the efficacy of anticancer agents with better solubility and bioavailability and reduced side effects. However, there is limited evidence in relation to the application of phytochemicals in cancer treatment, 
Particularly focusing on nanotechnology, therefore, in this review, first, we introduce the drug carriers used in advanced nanotechnology and their strengths and limitations. Second, we provide an update on well-studied nanotechnology-based anticancer therapies related to the carcinogenesis process, including signaling pathways related to transforming growth factor-β (TGF-β), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3 kinase (PI3K), Wnt, poly(ADP-ribose) polymerase (PARP), Notch, and Hedgehog (HH). Third, we introduce approved nanomedicines currently available for anticancer therapy. Fourth, we discuss the potential roles of natural phytochemicals as anticancer drugs. Fifth, we also discuss the synergistic effect of nanocarriers and phytochemicals in anticancer therapy.