Abstract

Inflammation occurs in response to host injury or infection, as the result of an autoimmune disease, or in response to the development of a tumor. Although the immune system may be helpful in fighting the tumor, it may also fuel the tumorigenic process. In fact, recent data suggest a strong link between chronic inflammation, angiogenesis, and the development of cancer. For example, inflammation and scarring caused by recurring infections with Mycobacterium tuberculosis may be a cause for cancers of the lung. Inflammatory breast cancer exhibits increased angiogenesis and lymphangiogenesis and has a higher metastatic potential than noninflammatory breast cancer. Nonsteroidal anti-inflammatory drugs have been proposed as preventives for the development of colon carcinoma and ovarian cancer. Inhibition of nuclear factor-kappaB contributes to the proposed mechanism of action. Inflammatory cytokines, including interleukin-6, serve as autocrine and paracrine growth factors for several cancers, and high levels of these cytokines may correlate with a poor prognosis and increased production of angiogenic factors. The state of the art of our understanding of this critical interaction is reviewed.