Carcinoembryonic Antigen Monitoring to Detect Recurrence of Colorectal Cancer: How Should We Interpret the Test Results?

[摘要] To the Editor:It is routine clinical practice, supported by national guidelines in both North America and Europe, to measure blood carcinoembryonic antigen (CEA)1 to detect recurrence of colorectal cancer during follow-up after primary treatment. Blood CEA is usually measured every 3–6 months, and patients with a CEA concentration above an absolute threshold (5 μg/L according to American Society of Clinical Oncology guidelines) are investigated further by radiological imaging. However, the evidence underpinning both guidelines and routine practice is weak.We recently reported the interim results of the Follow-up After Colorectal Surgery (FACS) trial, a clinical trial comparing different types of posttreatment follow-up in 1200 patients with colorectal cancer (1). This trial confirmed that measuring CEA is an effective way of detecting recurrence at an early stage, thus increasing the number of recurrences that can be treated with curative intent. However, the threshold we applied to define an abnormal CEA concentration (7 μg/L above the patient's postoperative concentration at trial entry) was more conservative than current guidelines, so we decided to reevaluate our data to assess retrospectively whether we could have done better by applying a different strategy to interpret the CEA …

[学科分类] 过敏症与临床免疫学