Targeting the tumor microenvironment as a potential therapeutic approach in colorectal cancer: Rational and progress

Colorectal cancer (CC) is often diagnosed at a late stage when tumor metastasis may have already occurred. Current treatments are often ineffective in metastatic disease, and consequently late diagnosis is often associated with poor outcomes in CC. Alternative strategies are therefore urgently required. An interaction between epithelial cancer cells and their tissue microenvironment is a contributor to metastasis, and therefore recent studies are beginning to focus on the properties of the tumor microenvironment and the mechanism by which the metastatic cells exploit the tumor microenvironment for survival, immune evasion, and growth. We have reviewed the development of the combined therapeutic approaches that have focused on targeting the microenvironment of CC.