CEACAM5 and colorectal cancer: Glycoproteins facilitate tumor spread by allowing tumor cells to adhere to and migrate through the extracellular matrix and vascular endothelium.[15] While carcinoembryonic antigen (CEA) is widely used as a biomarker for colorectal cancer, elevated CEA levels have also been detected in certain BC patients, making it a potential surveillance and prognostic marker.[16]