Advances in Immunological Combination Therapy for Colorectal Cancer

Immune checkpoint inhibitors (ICIs) have been utilized extensively and shown to be therapeutically beneficial in the treatment of solid tumors in recent years. Nonetheless, considerable heterogeneity in Colorectal cancer (CRC) requires careful consideration. ICIs monotherapy demonstrated notable therapeutic effects in microsatellite unstable mismatch repair‐deficient (MSI‐H/dMMR) CRC with high immunogenicity and tumor mutation load (TMB); however, the response rate of ICIs monotherapy was low in microsatellite stable mismatch repair‐normal (MSS/pMMR) CRC with low TMB and immunosuppressive microenvironment. This article introduces the application status of ICIs monotherapy in CRC, and proposes that combined immunotherapy may be the key to solving its drug resistance. Then it summarizes the exploration and progress of CRC immunotherapy combined with radiotherapy, chemotherapy, targeted therapy, intestinal flora, oncolytic virus, tumor vaccine, and other treatments in recent years, and looks forward to the future research direction and application prospect of combined immunotherapy.