Carcinoembryonic Antigen (CEA) in Cancer Diagnosis and Monitoring

Diagnostic Performance and Clinical Applications

The American Society of Clinical Oncology recommends against using CEA for cancer screening or diagnosis due to its low sensitivity and specificity, particularly for early-stage disease 1, 2, 5
For colorectal cancer, only 50-60% of patients with metastatic disease will have elevated CEA levels, highlighting its limited sensitivity 1, 3
The American Society of Clinical Oncology suggests that preoperative CEA may be ordered in patients with colorectal carcinoma for prognostic information and to establish a baseline for postoperative surveillance 5, 6
Postoperative CEA testing is recommended every 3 months in patients with stage II or III colorectal cancer for at least 3 years if the patient is a candidate for surgery or systemic therapy 5
For monitoring patients with metastatic colorectal cancer during active therapy, CEA is the marker of choice and should be measured at the start of treatment and every 1-3 months during active treatment 5, 6
The American Society of Clinical Oncology advises caution when interpreting rising CEA levels during the first 4-6 weeks of a new therapy, as spurious early rises may occur 1, 5

CEA is elevated in multiple non-cancer conditions, and its levels increase with age, which can confound interpretation 7
When evaluating potential malignancy, additional tumor markers should be considered alongside CEA, such as CA-125 and CA 19-9, to improve diagnostic accuracy 7

For breast cancer, CEA is not recommended for screening, diagnosis, staging, or routine surveillance after primary therapy, but can be used in conjunction with other methods for monitoring metastatic disease during active therapy 1, 3