AB057. SOH23ABS_188. PDL-1 expression based on aetiology of mismatch repair deficiency— are there differences between molecularly lynch and sporadic colorectal cancer?

Background: Data regarding the response of Lynch syndrome (LS) colorectal cancer (CRC) to immune checkpoint inhibitors (ICIs) is scarce. Aim: to investigate differences in clinicopathological, local and systemic inflammation and programmed death-ligand 1 (PD-L1) expression as measured in tumour [Tumour Proportion Score (TPS)] and tumour plus immune cells [Combined Positive Score (CPS)] relative to all viable tumour cells.