Conclusions:
Alteration of the DDR pathway was strongly associated with MSI status in CRC. • DDR-MT was more prevalent in right-sided tumors compared to left-sided tumors. • Elevated TMB and PD-L1 expression in DDR-MT CRC indicate more activated anti-tumor immune profiles compared to DDR-WT, regardless of MSI status, suggesting possible therapeutic benefit from immune checkpoint inhibitors in DDR-MT CRC.