Colon and rectal cancer are different tumor entities according to epidemiology, carcinogenesis, molecularand tumor biology, primary and secondary prevention: preclinical evidence

Introduction. Colon and rectal cancer (CC, RC) are different entities from a clinical and tumor biological point of view. Up to now, both, CC and RC, are synonymously called “Colorectal Cancer” (CRC). With our experience in basic and clinical research and routine work in this field we now have come to the opinion, that the term “CRC” should definitely be questioned, and if justified, be abandoned. materials/methods. We analyzed the actual available data from the literature and our own results from the Ulm based study group FOgT to proof or reject our hypothesis. results. The following evident differences were recognized: Anatomically, the risk to develop RC is 4× higher than for CC. Molecular changes in carcinogenesis in CC are different from RC. Physical activity helps to prevent CC, not RC. Pathologically there are differences between RC and CC. In addition, there are also major clinical differences between CC and RC, such as in surgical topography and- procedures, multimodal treatment (MMT) approaches (RC in MMT is less sensitive to chemotherapy than CC), and prognostic factors for the spontaneous course and for success of MMT (e.g. TS or DPD). discussion. CC´sand RC´s definitely are different in parameters of causal and formal carcinogenesis, effectivity of primary prevention by physical activity, conventional and molecular pathology.According to our findings we can demand from the preclinical point of view that CC and RC are two different tumor entities in terms of various representative biological characteristics.CC and RC are also differing substantially in many clinical features, as outlined in a separate paper from our group. Conclusion. “CRC” should no longer be used in basic and clinical research and other fields of cancer classification as a single disease entity. CC is not the same as RC. CC might even be divided into right and left CC.