Published online Jul 28, 2016. doi: 10.3748/wjg.v22.i28.6362
Peer-review started: March 25, 2016
First decision: May 12, 2016
Revised: June 2, 2016
Accepted: June 15, 2016
Article in press: June 15, 2016
Published online: July 28, 2016
Processing time: 119 Days and 10.8 Hours
Human colorectal cancer (CRC) is the third most commonly diagnosed malignancies and the prognosis for patients with recurrent or metastatic disease is extremely poor. Although new chemotherapeutic regimen improves survival rates, therapy with better efficacy and less adverse effects is drastically needed. Immunotherapy has been investigated in human CRC for decades with limited success. However, recent developments of immunotherapy, particularly immune checkpoint inhibitor therapy, have achieved promising clinical benefits in many types of cancer and revived the hope for utilizing such therapy in human CRC. In this review, we will discuss important immunological landscape within the CRC microenvironment and introduce immunoscore system to better describe immunophenotyping in CRC. We will also discuss different immunotherapeutic approaches currently utilized in different phases of clinical trials. Some of those completed or ongoing trials are summarized. Finally, we provide a brief prospective on the future human CRC immunotherapy.
Core tip: Immunotherapy has recently achieved great clinical objective response in multiple cancer types. However, immunotherapy in human colorectal cancer (CRC) is still in its infancy. Identifying CRC patients who are responding to different forms of immunotherapy is drastically needed. In this review, we will discuss important immunological landscape within the CRC microenvironment and introduce immunoscore system to better describe immunophenotyping in CRC. Knowledge gained from these studies may provide rational design for immunotherapy in human CRC patients.