An Immunoscore System Based On CD3(+) And CD8(+) Infiltrating Lymphocytes Densities To Predict The Outcome Of Patients With Colorectal Adenocarcinoma

PURPOSE: The aim of this study was to evaluate the Immunoscore (IS) methodology as a prognostic marker of colorectal adenocarcinoma in Tunisian population. Tumor blocks were retrospectively collected from 106 patients with sporadic colorectal cancer. METHODS: Immunohistochemical staining and images analysis software were used to quantify the density of CD3(+) and CD8(+) tumor-infiltrating lymphocytes in the center of the tumor and invasive margin. RESULTS: The density of CD3(+) and CD8(+) was significantly associated with 5-year overall survival (P=0.001 and P=0.00098, respectively) and 5-year disease-free survival (P=0.0006 and P=0.0056, respectively). The earlier stage and the absence of vascular emboli showed a significant association with IS analysis. Cox multivariate regression analysis revealed that Immunoscore (from I0 to I4) was more significantly correlated with overall survival (P=0.00011) and disease-free survival (P=0.0008) than Tumor-Node-Metastasis (TNM) staging (P=0.057 and P=0.039, respectively). Patients with low IS were associated with inferior disease-free survival and overall survival, contrary to patients with high IS. CONCLUSION: This is the first study which evaluated the prognostic value of IS methodology in colorectal cancer in African and Arabic population. The IS methodology carries out in this study allows to estimate the risk of relapse in patients with colorectal cancer. Overall, our results support the implementation of the consensus Immunoscore as a new component for the classification of cancer, designated TNM-Immune.