CEACAM5 and colorectal carcinoma: The results showed that, compared with serum CEA levels, the AUC of the cfDNA adsorption rate in CRC, LC, GC, and EC was better than CEA (CRC cfDNA vs. CEA, 0.7980 vs. 0.7936, LC cfDNA vs. CEA, 0.7773 vs. 0.6922, GC cfDNA vs. CEA, 0.6788 vs. 0.6211 and EC cfDNA vs. CEA, 0.8033 vs. 0.5918).