Conventional chemotherapeutic drugs for cancer treatment generally result in serious side effects and deteriorate the qualities of life of patients. Due to their nonspecific distribution via systemic administration, the drugs cause toxicity to both malignant tumor and normal cells. Cancer nanotheranostics (therapeutics and diagnostics in nanomedicine) is emerging as a promising therapeutic prototype and gaining more interest in the drug delivery research field and medical profession. This article gives an overview and discussions on adverse effects from recent chemotherapeutic drugs, understanding abnormality of tumor blood vasculature leading to design and development of nanocarriers to avoid entering into normal tissue, and their transport process to reach the targeted cancer cells. Biological barriers to successful delivery
of the drugs to cancer cells and how to bypass such barriers are also described. The advantage of nanotheranostics intrinsic properties that integrate diagnostic and therapeutic functions in one system would enhance targeted therapeutic efficacy compared with traditional drug delivery carriers. Certain issues of several nanocarriers, recent research works to overcome their limitations and the role of nanotheranostics in personalized cancer therapy, which is a new trend in future medicine, are also reviewed.