Molecular mechanisms of inflammation-induced carcinogenesis

Chronic inflammation has been thought as the major risk factor for various types of human cancer. The International Agency for Research on Cancer (IARC) has estimated that approximately one-fifth of cancer cases worldwide is attributable to infectious/inflammatory diseases. While we fundamentally understand that persistent inflammation plays a role in carcinogenesis, recent advances in the molecular study of the mechanisms have revealed that reactive oxygen and nitrogen species, harmful endogenous genotoxic substances, produced by inflammatory cells are largely involved in the carcinogenic process. In this article, we review the instances demonstrating the definite link between inflammation and cancer, and shed light on the molecular mechanisms proved to be responsible for the inflammation-based carcinogenesis.