Cancer-induced immunosuppression: implications for therapy?

Cancer-induced immunosuppression can be caused by a variety of effects. These include factors produced by the host in response to the presence of tumor or factors elaborated by the tumor itself. Disseminated tumor can lead to host debility with associated anergy. Some immunosuppressive effects are due to the manner in which the host processes (or fails to process) the tumor as an antigenic stimulus. Lastly, antitumor treatments can have a detrimental impact on host antitumor immunity. Recent research findings from our laboratories implicate surgical stress effects and tumor-mediated production of growth factors such as transforming growth factor beta (TGF-beta) as being important causes of host immune impairment. An accurate understanding of the mechanisms underlying host antitumor immune impairment will be critical in the successful development of immunotherapy strategies for use in the surgical oncology patient.