The nurse is working in an oncology clinic caring for a patient currently undergoing treatment for colorectal cancer. Which of these tumor markers would most likely be used to monitor the patient’s disease?

Specific tumor markers have become increasingly standard in the detection and monitoring of certain types of cancers. In the case of colorectal cancer, CEA is frequently used to monitor disease progression (and response to treatment), but it is not used to diagnose the condition. PSA is often elevated in prostate cancer and may be used for both detection and monitoring. HCG levels may be elevated in some cases of testicular cancer along with certain gestational trophoblastic tumors. Alpha fetoprotein is often elevated in hepatocellular carcinoma and other hepatic diseases. It may also be elevated in cases of testicular cancer.