Therapeutic approaches to cancer-associated immune suppression

It is now well established that many cancer patients exhibit in vivo and in vitro evidence of immune suppression, which often correlates with tumor-cell burden, stage of disease, and prognosis. Cancer-associated immune suppression appears to be a direct result of the presence of disease, or follows treatment for it, rather than being an antecedent or predisposing condition. However, the precise role that nonspecific and/or specific antitumor immunity plays in the control of human cancer remains controversial. Indeed, there is some evidence that suggests that the development of certain antitumor immune responses may lead to augmented tumor cell growth rather than tumor regression [314,442,443].