Integrative analyses of colorectal cancer show Immunoscore is a stronger predictor of patient survival than microsatellite instability

Significant differences in mutational patterns, chromosomal instability and gene expression were found that correlated with microsatellite instability status. A prominent immune gene expression programme was observed in microsatellite-unstable tumours and in a subgroup of microsatellite-stable tumours. Unstable tumours had increased frameshift mutations, genetic evidence of immunoediting, higher densities of T-helper-1, effector-memory and in situ proliferating T cells and of inhibitory PD-1 and PD-L1 cells, high Immunoscores, and infiltration with mutation-specific cytotoxic T cells. In multivariate analysis, Immunoscore was superior to microsatellite instability in predicting disease-specific recurrence and survival.