Infection and cancer: the common vein

The role of infectious agents in the development of cancer is well documented. The pathogenesis of various human neoplasms ranging from non-Hodgkin lymphoma (NHL) to cervical carcinoma frequently involves a chronic, most often viral, infection. At the same time, there is compelling evidence that certain acute infections result in the inhibition of neoplastic growth. The basis for this phenomenon is often thought to be concomitant anti-tumor immunity. Yet, experimental data supporting this hypothesis are scarce, and other non-immune anti-tumor factors could be involved. For instance, since virtually all aggressive tumors outstrip their blood supply, development of new vessels, or angiogenesis, is a limiting factor during neoplastic growth. In this review, we will discuss recent studies that implicate anti-angiogenesis in infection-mediated tumor suppression and suggest that this mechanism could also complement cytotoxic immunity arising from the use of cancer vaccines.