Targeted cancer immunotherapy.

The understanding that the immune system plays a dual role in cancer progression has led to the recent development of targeted immunotherapies. These treatments, which aim to harness the immune system against cancer, include monoclonal antibodies, immune adjuvants, cell-based therapy and vaccines. Although numerous immune-targeted treatment modalities have entered the clinic, most have shown limited efficacy. The intrinsic heterogeneity and genomic instability of the tumor, coupled with immune suppression induced by both the tumor and its microenvironment, remain the main obstacles to the success of these therapies. We believe that the primary objective of the new generation of therapies must be to reinstate immune surveillance against primary and metastatic tumor cells, while inhibiting the immune suppressive microenvironment. Most probably this will be achieved by combining several treatment modalities. This paper will briefly review current immunotherapies and their promise, as well as the obstacles associated with them.