Cytokine Gene Polymorphism and Cancer Risk: A Promising Tool for Individual Susceptibility and Prognostic Implications

Cytokines are potent molecules produced mainly by specific activated immune cells to control inflammatory responses besides other biologic processes. Although active participation of cytokines provides defense against carcinogenesis on the other hand, deregulation at the genetic level influences their activity to promote tumor development. Among many aspects, constitutional polymorphic sequence variations are key factors that derange the cytokine expression to lead an individual’s propensity to risk for different cancers. Cytokine polymorphisms are now believed to alter these critical molecules that have a dual face in carcinogenesis as, when implicated in the activation of the immune response, these molecules check the cancer development while their persistent inflammatory reaction can envisage the development of malignancy and tumor growth. We have given ample evidence of case-control studies in a range of cancers where substantial evidence, as reported in this chapter, links polymorphism of cytokine gene susceptibility with numerous cancers. Cytokine gene polymorphism is vital to be significant bimolecular genetic determinants of susceptibility and prognosis of cancer. A strong need is felt for more case-control association studies in cytokine candidate genes involved in specific pathways for particular cancer in bigger powered sample sizes involving additional variables to disclose their factual risk for cancer.