These results suggested that ICI treatment may be more effective in patients with UC-associated dysplasia/colitic cancer with distant metastases after total colectomy who are not at a risk for ICI-induced colitis than in patients with SCRC, because patients with UC-associated dysplasia/colitic cancer exhibit clinical characteristics including favourable ICI responses, “hot tumour” immune phenotypes, including high PD-L1/high CD8+ CTLs, and high IRF-1 expression. Here, CD8A is linked to colitis.