Mohammad Mostafa Mohammadi Yekta - Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran

Colorectal cancer (CRC) is one of the most important leaders in cancer mortality. Despite extensive research, the precise etiology, molecular pathogenesis and exact treatment are still unknown. One of the triggers in CRC occurrence is the chronic inflammation of colon and rectum and researchers suggest that there is a relation between chronic inflammation and CRC that is still unknown. A search in Pubmed and google scholar based on the articles that have discussed the relation between inflammation and CRC between 2000 till 2015 was conducted‪. †Studies have showed that patients with long-standing inflammatory disease (IBD) have an increased risk of developing CRC. Also, it has been suggested that intestinal flora plays a role in developing CRC. To explain the reason for this issue, researchers suggest an unknown interaction between intestinal flora and dietary factors that lead to a chronic inflammation. This inflammation induces CRC. To understand the colorectal cancer, it is better to focus on colorectal inflammations first. Studies show that Interleukin-6 (IL-6) signaling acts as an inducer of tumor growth in colorectal cancers. Also it has been demonstrated that IL-6 is produced by an induction caused by IL-23 that is essential for T-cell mediated colitis and inflammation. Another factor is TGF-β, which suppresses tumor progression in CRC by inhibiting IL-6 signaling. IL-6 serum levels have been significantly elevated in patients with CRC. This article has tried to explain the relation between cytokines and the development and occurrence of colorectal cancer.

Colorectal Cancer, Cytokines, TGF-β, Interleukin-6, Intestinal Flora