Immunoscore and its introduction in clinical practice

Abstract

Current cancer classification is based on intrinsic tumor parameters such as characteristic of tumor cells, tumor progression, tumor invasion and the presence of distant metastases, as summarized by the AJCC/UICC-TNM stratification system. There is currently no immune-based classification of cancer. We provided evidence that the immune contexture, as defined by the type, density, functional immune orientation and the location of immune cells within tumor, strongly influences the outcome of colorectal cancer (CRC) patients. To translate this information to the clinic, we developed an immunohistochemistry and digital pathology-based assay named Immunoscore that allows the quantification of two T cell subsets (CD3 and CD8) in two tumor regions (core and invasive margin of tumors). We have demonstrated that the standardized consensus Immunoscore has a prognostic value superior and independent to the one of the traditional TNM system in an international study in stage I-III colon cancer patients, therefore validating the Immunoscore as the first immune-based scoring system. In additional analyses, we showed the prognostic value of Immunoscore for stage II-IV CRC patients, as well as the predictive value of Immunoscore in stage III colon cancer patients. The Immunoscore may help predict and stratify patients who will benefit from adjuvant chemotherapy. Moreover, the Immunoscore allows the classification of tumors from hot to cold categories, and could consequently guide clinical decision for the choice of treatment.