The aim of our study was, first, to determine using two randomised subgroups (n=543 and n=501) whether TOPK expression leads to reproducible associations with clinicopathological features by immunohistochemistry (IHC) and, second, to determine according to KRAS and BRAF gene status the prognostic effect of TOPK on 222 sporadic and 71 Lynch syndrome-associated CRC patients, as well as the prognostic and predictive value of TOPK in 45 metastatic CRC patients treated with anti-EGFR agents, cetuximab and panitumumab. Here, BRAF is linked to Lynch syndrome.