Which test is commonly used to monitor treatment of colon cancer?

Which test is commonly used to monitor treatment of colon cancer?

• A. Immunonephelometry
• B. Serum protein electrophoresis
• C. Carcinoembryonic antigen
• D. Alpha-fetoprotein

Answer: (C)

Tracking how well colon cancer responds to treatment relies on a tumor marker that reflects the amount of cancer in the body over time. Carcinoembryonic antigen (CEA) is used for this purpose because many colon cancers secrete CEA, so serial measurements can show whether tumor burden is decreasing with therapy or if it’s rising, suggesting progression or recurrence. A falling CEA level during treatment generally indicates a good response, while a rising level can prompt further imaging or a change in therapy. It’s important to interpret CEA trends rather than rely on a single value, since some patients do not secrete CEA and levels can be affected by factors like smoking or other diseases. The other options aren’t used for monitoring colon cancer. Immunonephelometry is a technique to measure proteins in a sample, not a marker of disease activity. Serum protein electrophoresis analyzes protein patterns to help diagnose conditions like gammopathies or liver issues, not specifically to track colon cancer. Alpha-fetoprotein is a marker more relevant to hepatocellular carcinoma and certain germ cell tumors, not colon cancer.

Tracking how well colon cancer responds to treatment relies on a tumor marker that reflects the amount of cancer in the body over time. Carcinoembryonic antigen (CEA) is used for this purpose because many colon cancers secrete CEA, so serial measurements can show whether tumor burden is decreasing with therapy or if it’s rising, suggesting progression or recurrence. A falling CEA level during treatment generally indicates a good response, while a rising level can prompt further imaging or a change in therapy. It’s important to interpret CEA trends rather than rely on a single value, since some patients do not secrete CEA and levels can be affected by factors like smoking or other diseases.

The other options aren’t used for monitoring colon cancer. Immunonephelometry is a technique to measure proteins in a sample, not a marker of disease activity. Serum protein electrophoresis analyzes protein patterns to help diagnose conditions like gammopathies or liver issues, not specifically to track colon cancer. Alpha-fetoprotein is a marker more relevant to hepatocellular carcinoma and certain germ cell tumors, not colon cancer.