Systematic review and network meta-analysis of prognostic value of combined TIL-status and MSI-status in colorectal cancer

Impaired DNA repair mismatch activity and corresponding phenotypes (MSI en MSS) are strongly associated with colorectal cancer (CRC) survival and can guide therapy decisions. Although highly correlated with MSI status, tumor infiltrating lymphocytes (TILs) are independently prognostic in CRC. A network meta-analysis of 19 studies (13,029 patients) evaluated the prognostic role of various combinations of MSI-TIL status. For overall survival, as well as for disease-free survival and for cancer-specific survival, the MSI-TIL-H subtype had the best prognosis, closely followed by MSS-TIL-H. Conversely, tumors with poor lymphocytic infiltration had poor survival outcomes in both MSI and MSH tumors. The authors conclude that tumor immune context outperforms the MSI classification system, and thus largely influences the prognosis of patients with curatively resected CRC.