Are Colon and Rectal Cancer Two Different Tumor Entities? A Proposal to Abandon the Term Colorectal Cancer

Abstract

Colon cancer (CC) and rectal cancer (RC) are synonymously called colorectal cancer (CRC). Based on our experience in basic and clinical research as well as routine work in the field, the term CRC should be abandoned. We analyzed the available data from the literature and results from our multicenter Research Group Oncology of Gastrointestinal Tumors termed FOGT to confirm or reject this hypothesis. Anatomically, the risk of developing RC is four times higher than CC, while physical activity helps to prevent CC but not RC. Obvious differences exist in molecular carcinogenesis, pathology, surgical topography and procedures, and multimodal treatment. Therefore, we conclude that CC is not the same as RC. The term "CRC" should no longer be used as a single entity in basic and clinical research as well as other areas of classification.

Keywords: colon cancer; colorectal cancer; rectal cancer.

Figure 1

Comparison of the incidences of depressed and non-depressed types of neoplastic lesions in the rectum, the left colon, and the right colon. (a) Mucosal lesions; (b) submucosal cancers. A significant difference in the macroscopic type was noted between the rectum and the colon (p < 0.001). The incidence of depressed submucosal cancers in the right colon was significantly higher than that in the rectum (p = 0.0472); (c) Relationship between the location and the size of non-depressed mucosal lesions; (d) Relationship between the location and the incidence of villous components in non-depressed mucosal lesions; (e) Locations of mucosal lesions and submucosal cancers. (Adapted from Konishi et al. 1999 [28].)