Carcinoembryonic Antigen in the Staging and Follow-up of Patients with Colorectal Cancer
Carcinoembryonic Antigen in the Staging and Follow-up of Patients with Colorectal Cancer
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DOI：
10.1081/cnv-58878
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发表时间：
2005-01
影响因子：
2.4
通讯作者：
M. Goldstein;E. Mitchell
中科院分区：
文献类型：
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作者：
M. Goldstein;E. Mitchell
CEA是一种复杂的糖蛋白，由90%的结直肠癌产生，并有助于肿瘤的恶性特征。它可以在血清中定量测量，其在血浆中的水平可以用作疾病的标志物。由于其在结直肠癌的早期阶段缺乏敏感性，CEA测量是一个不适合的模式，人口筛查。术前CEA升高是一个预后不良的信号，与结直肠癌手术切除后总生存率降低相关。手术切除后CEA未能恢复到正常水平表明隐匿性系统性疾病切除不充分。术后频繁监测CEA可以识别转移性疾病患者，手术切除或其他局部治疗可能对这些患者有益。为了确定这组，连续CEA测量似乎比临床评估或任何其他诊断方式更有效，尽管其检测复发性疾病的灵敏度对于局部或肺转移不如对于肝转移那么高。几项研究表明，一小部分患者术后进行CEA监测，并接受CEA指导的转移性疾病挽救手术，术后5年仍存活且无病。此外，补救手术后CEA水平似乎可以预测接受肝或肺转移瘤切除术患者的生存率。然而，一些作者认为，CEA监测在挽救生命方面并不具有成本效益。为了支持这一论点，在转移性疾病切除术后，在CEA水平升高的基础上进行二次探查手术的患者与其他实验室或影像学异常的患者之间，以治愈为目的的生存率没有明显差异。关于CEA监测的频率或持续时间也没有明确的共识，尽管ASCO指南目前建议在诊断后至少2年内每2-3个月进行一次。在接受姑息治疗的患者的随访中，CEA水平与反应良好相关，CEA不仅指示反应，而且还可以识别疾病稳定的患者，对于这些患者，联合化疗在生存和症状缓解方面也有明显的益处。最近，放射性标记抗体给药后的结肠造影成像提供了一种重要的放射性核素技术，该技术在评估结肠直肠癌患者疾病的程度和位置方面增加了临床重要信息，超过或补充了常规成像方式。基于CEA的免疫疗法是证明抗体和T细胞应答的临床研究的快速发展领域。
CEA is a complex glycoprotein produced by 90% of colorectal cancers and contributes to the malignant characteristics of a tumor. It can be measured in serum quantitatively, and its level in plasma can be useful as a marker of disease. Because of its lack of sensitivity in the early stages of colorectal cancer, CEA measurement is an unsuitable modality for population screening. An elevated preoperative CEA is a poor prognostic sign and correlates with reduced overall survival after surgical resection of colorectal carcinoma. A failure of the CEA to return to normal levels after surgical resection is indicative of inadequate resection of occult systemic disease. Frequent monitoring of CEA postoperatively may allow identification of patients with metastatic disease for whom surgical resection or other localized therapy might be potentially beneficial. To identify this group, serial CEA measurement appears to be more effective than clinical evaluation or any other diagnostic modality, although its sensitivity for detecting recurrent disease is not as high for locoregional or pulmonary metastases as it is for liver metastases. Several studies have shown that a small percentage of patients followed postoperatively with CEA monitoring and who undergo CEA-directed salvage surgery for metastatic disease will be alive and disease-free 5 years after surgery. Furthermore, CEA levels after salvage surgery do appear to predict survival in patients undergoing resection of liver or pulmonary metastases. However, several authors argue that CEA surveillance is not cost-effective in terms of lives saved. In support of this argument, there is no clear difference in survival after resection of metastatic disease with curative intent between patients in whom the second-look surgery was performed on the basis of elevated CEA levels and those with other laboratory or imaging abnormalities. There is also no clear consensus on the frequency or duration of CEA monitoring, although the ASCO guidelines currently recommend every 2-3 months for at least 2 years after diagnosis. In the follow-up of patients undergoing palliative therapy, the CEA level correlates well with response, and CEA is indicative of not only response but may also identify patients with stable disease for whom there is also a demonstrated benefit in survival and symptom relief with combination chemotherapy. More recently, scintigraphic imaging after administration of radiolabeled antibodies afforded an important radionuclide technique that adds clinically significant information in assessing the extent and location of disease in patients with colorectal cancer above and beyond or complementary to conventional imaging modalities. Immunotherapy based on CEA is a rapidly advancing area of clinical research demonstrating antibody and T-cell responses.