Abstract
Cancers remain difficult to treat despite recent advances in cancer therapy, including new surgical options and advances in chemotherapy, radiotherapy and gene therapy. Treatment is aimed at controlling advanced and metastatic cancers and preventing recurrence. A number of promising new chemotherapeutic agents have been developed and, to reduce the side effects of chemotherapy, tumor-selective delivery vectors have been also developed. However, it is impossible to kill all the cancer cells by anti-cancer reagents. Thus, cancer immunotherapy is gaining interest. Although current immunotherapy can reduce, delay, or prevent tumor recurrence, many tumors still progress due to the development of mechanisms to avoid recognition and elimination by the immune system. Therefore, it is expected that immunotherapy might be used to eradicate residual cancer cells following therapy to reduce tumor volume. A number of studies suggest that both tumor regression and anti-tumor immunity are required for complete tumor eradication. To achieve both tumor regression and anti-tumor immunity without causing serious side effects, tissue-targeted drug delivery vectors with beneficial adjuvant properties will be required in the future.
