Immunotherapy for colorectal cancer

Immunotherapy for colorectal cancer has been under investigation for many years. Many recent scientific advances contribute to the success of cancer immunotherapy, including our better understanding of anti-tumor immune response, tolerance and regulation, and the advent of newer therapies including agonist antibodies to the co-stimulatory molecules targeting T cells. Immunotherapy may represent a novel effective treatment for colorectal cancer patients. Many preclinical data have provided the basis of immunotherapy of colorectal cancer, demonstrating the potential benefit for patients. With the success of immunotherapy such as ipilimumab and programmed death-1 (PD-1) pathway-targeted agents, activating the immune system for the treatment of colorectal cancer has become more promising. In this article, we review the immune responses against tumors and summarize the preclinical and early clinical data on colorectal cancer immunotherapy. We will also discuss possible strategies and recent progress in immunotherapy for colorectal cancer, in particular, vaccines, passive transfer of anti-cancer monoclonal antibodies and donor T cells. Continued advances in antibody and T cell engineering should further help improve treatment outcomes of colorectal cancer.