Which tumor marker is used for colorectal cancer?

Carcinoembryonic antigen (CEA) is specifically utilized in the management of colorectal cancer. It is a glycoprotein that is typically elevated in patients with colorectal cancer, among other malignancies. CEA levels can be monitored to assess the effectiveness of treatment and to check for recurrence after surgical resection of the tumor.

In comparison to other options, while CA 19-9 is primarily used as a marker for pancreatic cancer, alpha-fetoprotein is associated with liver cancer and germ cell tumors, and AFP-L3 is a subtype of alpha-fetoprotein that is used in the context of liver cancer and hepatocellular carcinoma. Thus, these markers do not specifically relate to colorectal cancer, distinguishing CEA as the most relevant marker in this case.