Clinical significance of interleukin-6 (IL-6) as a prognostic factor of cancer disease

Interleukin-6 (IL-6) is proinflammatory cytokine that produces multifunctional efects. It is also involved in the regulation of immune reactions, hematopoiesis and inflammatory state. Interleukin-6 has been shown to be associated with tumor progression including inhibition of cancer cells apoptosis and stimulation of angiogenesis. Anti-IL-6 therapy is a new strategy in the inflammatory autoimmune diseases and cancer. Clinical studies have shown elevated serum IL-6 concentrations in patients with endometrial cancer, non-small cell lung carcinoma, colorectal cancer, renal cell carcinoma, breast and ovarian cancer. Serum IL-6 levels correlate with tumor stage, and survival of patients. In this article we have focused on a role of IL-6 as a prognostic factor in several malignancies such as colorectal cancer, breast cancer, gastric cancer and pancreatic cancer.