CEACAM5 and neoplasm: Notably, both groups did not show statistically significant differences regarding gender, age, pT and pN status as well as localisation of the primary tumour (colon vs rectum), extent of distant metastasis (one vs more than one site) or CEA serum levels at diagnosis, and showed indistinguishable rates of proliferation (i.e. averaged sample-wide Ki67 reactivity) and apoptosis (i.e. mean frequency of cleaved caspase-3-positive cells) (data not shown).