Immune contexture and cancer prognosis (88.28)

Abstract To date the anatomic extent of tumor (TNM classifications) has been by far the most important factors to predict the prognosis of colorectal cancer patients. However, the impact of immune responses and tumor escape on patient prognosis in human cancer is poorly understood. We showed that tumors from human colorectal cancer with a high density of infiltrating memory and effector memory T-cells (TEM) are less likely to disseminate to lymphovascular and perineural structures and to regional lymph-nodes. We showed that the combination of immune parameters associating the nature, the density, the functional orientation and the location of immune cells within the tumor was essential to accurately define the impact of the local host immune reaction on patients prognosis. We proposed to define these immune criteria as "immune contexture". Investigation of the CRC primary tumor microenvironment allowed us to uncover the association of favorable outcomes with efficient coordination of the intratumoral immune response. We described four major immune coordination profiles within CRC primary tumors depending on the balance between tumor escape and immune coordination. In conclusion, the density and the immune-cell location within tumor regions had a prognostic value that was superior of those of the TNM classifications. Tumor invasion was dependent on the host immune reaction.