Published online Sep 21, 2014. doi: 10.3748/wjg.v20.i35.12407
Revised: March 19, 2014
Accepted: May 19, 2014
Published online: September 21, 2014
Processing time: 302 Days and 2.2 Hours
The potential clinical impact of enhancing antitumor immunity is increasingly recognized in oncology therapeutics for solid tumors. Colorectal cancer is one of the most studied neoplasms for the tumor-host immunity relationship. Although immune cell populations involved in such a relationship and their prognostic role in colorectal cancer development have clearly been identified, still no approved therapies based on host immunity intensification have so far been introduced in clinical practice. Moreover, a recognized risk in enhancing immune reaction for colitis-associated colorectal cancer development has limited the emphasis of this approach. The aim of the present review is to discuss immune components involved in the host immune reaction against colorectal cancer and analyze the fine balance between pro-tumoral and anti-tumoral effect of immunity in this model of disease.
Core tip: Immune reactions accompany all stages of colorectal carcinogenesis and cancer progression. Recent evidence has shown that innate immunity pathways play a fundamental role in maintaining colorectal epithelial homeostasis and confer antitumor protection. However an excessive and unresolved innate immune reaction is the base of chronic colitis which is a well-known risk factor for colorectal cancer. Once the tumor has developed a number of immune cells may either favorably take under control its growth (CD45RO+CD8+ T cells) or favor its progression and metastatic spread (T regulatory cells). A fine regulation of all antitumor immune components is therefore necessary to design a proper immune-based therapeutic approach in colorectal cancer care and prevention.