Immunotherapy for advanced melanoma: Current knowledge and future directions.

Melanoma is one of the most aggressive cancers and is responsible for a large proportion of skin cancer-related deaths. The recent development of novel immunotherapeutic approaches has led to great advances in melanoma therapy. Because melanoma cells often express tumor-specific neo-antigens, significant therapeutic effects are mediated via immunotherapy-induced activation of cytotoxic T lymphocytes (CTLs); however, the effects depend on the immune status of the patient. At present, various immunotherapies have been approved and new clinical trials are progressing. These immunotherapies act in several ways, including CTL brake release, induction of CTL activation, transfer of CTLs, and modification of the tumor microenvironment to facilitate CTL activation. In the near future, patient-tailored immunotherapies and combination therapies are expected. In addition, it is important to monitor the status of the patient's immune response when selecting the most effective immunotherapy strategy.