The comprehension of "what cancer is" was bespoke these two last decades, switching from the traditional centro-cellular vision of cancer to a new holistic vision which integrates the tumor microenvironment and its immune component. Although in both visions, the result is, in fine, the emergence of a clone of cancer cells whose genome is modified, the genesis of the emergence of this clone and of its expansion is quite different offering a new explanatory framework and allowing the design of new predictive bio-markers as well as the development of innovative therapies. Recent data demonstrate that the immune infiltrate of the tumor is determinant for the outcome of patients bearing a solid cancer. For the first time, patient' prognosis can be estimated, not only by the assessment of tumor criteria (TNM classification, genetic disorders) but also by the evaluation of the immune component of the tumor microenvironment, using novel methodologies such as the 'Immunoscore'. Taking account of parameters derived from the reaction of the host against his tumor is an additional step towards a so-called Personalized Medicine in patients with cancer.
Keywords: Immunoscore; biomarkers; cancer; colon; immunology; personalized medicine; predictive factors; rectum; therapeutic strategies.