Overview: Carcinoembryonic Antigen (CEA) TestIntroduction: The Carcinoembryonic Antigen Test measures CEA to monitor cancers like colorectal cancer, causing abdominal pain or weight loss. Following 2023 NCCN guidelines, it uses an immunoassay for high sensitivity, aiding in cancer screening. This test is critical for guiding treatment monitoring, assessing disease progression, and improving outcomes in immunology for patients with suspected colorectal cancer.
Other Names: CEA Assay, Colorectal Cancer Marker Test.
FDA Status: Laboratory-developed test (LDT), meeting immunology standards for diagnostic accuracy.
Historical Milestone: CEA testing began in the 1960s with cancer research. Immunoassays emerged in the 1980s, and by the 2000s, high-sensitivity assays improved monitoring accuracy.
Purpose: Monitors colorectal cancer, guides treatment, and assesses disease progression in patients with abdominal pain or weight loss.
Test Parameters: 1. Carcino Embryonic Antigen
Pretest Condition: No fasting required. Collect serum or plasma at any time. Report symptoms like abdominal pain or weight loss, and list medications like chemotherapy.
Specimen: 2-5 mL serum (SST) or 2-4 mL plasma (EDTA). Centrifuge within 1 hour. Transport in a biohazard bag within 8 hours.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document abdominal pain, weight loss, or family history of colorectal cancer. Include current medications, especially chemotherapy or targeted therapies.
Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for cancer treatment.
Procedural Considerations: Uses an immunoassay to measure CEA levels. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Benign conditions like inflammatory bowel disease may elevate CEA levels. Hemolysis or improper storage can degrade samples.
Clinical Significance: Elevated CEA levels indicate colorectal cancer progression, prompting chemotherapy or surgery. Normal levels suggest stable disease or remission.
Specialist Consultation: Consult an oncologist for result interpretation. A gastroenterologist referral is advised for colorectal cancer cases.
Additional Supporting Tests: Colonoscopy, abdominal CT, or CA 19-9 test to confirm colorectal cancer or assess disease extent.
Test Limitations: False positives may occur with benign conditions. Results require clinical correlation with imaging.
References: NCCN Colorectal Cancer Guidelines, 2023; Journal of Clinical Oncology, Benson AB, 2022.
