Colorectal Cancer Subtypes: Developmental Origin and Microenvironmental Regulation.

Cancer is a heterogeneous disease and many cancer types do not represent a single entity, but are composed of biologically and clinically diverse subtypes. The subtype affiliation can influence prognosis and response to therapy. Recently, a multicenter colorectal cancer (CRC) subtyping consortium introduced a consensus molecular classification system for CRC. This will be of great benefit for future basic and clinical research since it enables uniform categorization of CRC specimens across different institutes and studies. The biological conformity observed within each consensus molecular subtype (CMS) holds promise for the design of subtype-specific treatment regimens. Herein, we review the CMSs of CRC with a focus on how multiple parameters, such as the origin, developmental route, and microenvironmental regulation shape distinct subtypes.