How to conduct Carcinoembryonic Antigen (CEA) counseling?

Conducting Carcinoembryonic Antigen (CEA) Counseling

CEA should be monitored every 3 months for at least 3 years in patients with stage II or III colorectal cancer who are candidates for surgery or systemic therapy of metastatic disease. 1

Purpose and Clinical Utility of CEA Testing

• CEA is not recommended as a screening test for colorectal cancer due to its low sensitivity and specificity, particularly for early-stage disease 1, 2
• CEA may be ordered preoperatively in patients with colorectal carcinoma if it would assist in staging and surgical treatment planning 1
• While elevated preoperative CEA (≥5 ng/mL) may correlate with poorer prognosis, data are insufficient to support using CEA alone to determine adjuvant therapy 1
• CEA is the marker of choice for monitoring metastatic colorectal cancer during active therapy 1, 2

CEA Monitoring Protocol for Colorectal Cancer

Postoperative Surveillance

• Measure CEA every 3 months in patients with stage II or III disease for at least 3 years after diagnosis 1
• An elevated CEA, if confirmed by retesting, warrants further evaluation for metastatic disease 1
• Elevated CEA alone does not justify systemic therapy for presumed metastatic disease without additional confirmation 1
• Wait until chemotherapy is finished to initiate surveillance, as chemotherapy may falsely elevate CEA levels 1

Monitoring Response to Therapy

• For patients with metastatic disease, measure CEA at the start of treatment and every 1-3 months during active treatment 1, 2
• Persistently rising values above baseline suggest progressive disease even without corroborating radiographic evidence 1, 3
• Exercise caution when interpreting rising CEA levels during the first 4-6 weeks of a new therapy, as spurious early rises may occur, especially after oxaliplatin 1, 2

Counseling Patients About CEA Results

Explaining Elevated CEA

• Inform patients that CEA is elevated in multiple non-cancer conditions, which can confound interpretation 2, 4
• Explain that CEA levels increase with age, which can affect baseline values 2
• Emphasize that a single elevated value should be confirmed with retesting before initiating extensive workup 1

Discussing Limitations

• Only 50-60% of patients with metastatic colorectal cancer will have elevated CEA levels, highlighting its limited sensitivity 2, 5
• CEA should not be used alone for monitoring response to treatment but in conjunction with diagnostic imaging, history, and physical examination 1, 6
• For breast cancer patients, CEA is not recommended for screening, diagnosis, staging, or routine surveillance after primary therapy 1, 2

Documentation and Follow-up

• Document baseline CEA value before initiating treatment 1, 3
• Record CEA trend over time rather than focusing on individual values 6
• Establish a clear follow-up plan with scheduled CEA testing and imaging studies 1
• Document patient education regarding the meaning of CEA results and the importance of adherence to the monitoring schedule 1

Special Considerations

• In the absence of readily measurable disease, CEA may be the primary indicator of disease status 1, 6
• CEA has been shown to be the most cost-effective approach to detecting potentially resectable metastases from colon cancer 1
• Studies have shown that 64% of recurrences were detected first by CEA, more than other tests in standard follow-up batteries 1
• When interpreting CEA results, consider that CEA can be elevated in smokers and patients with inflammatory conditions 4, 7