What are the cause of elevated Carcinoembryonic antigen?

Elevated carcinoembryonic antigen (CEA) levels can be caused by various factors, primarily associated with malignancies, especially colorectal cancer. Other cancers, such as lung, breast, and pancreatic cancer, may also contribute to increased CEA levels. Additionally, non-cancerous conditions like smoking, inflammatory bowel disease, and liver cirrhosis can lead to elevated CEA. Therefore, while it can be a marker for cancer, elevated CEA is not exclusively indicative of malignancy and should be interpreted in the context of other clinical findings.