A Review of the Role of Carcinoembryonic Antigen in Clinical Practice

Abstract

Carcinoembryonic antigen (CEA) is not normally produced in significant quantities after birth but is elevated in colorectal cancer. The aim of this review was to define the current role of CEA and how best to investigate patients with elevated CEA levels. A systematic review of CEA was performed, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified from PubMed, Cochrane library, and controlled trials registers. We identified 2,712 papers of which 34 were relevant. Analysis of these papers found higher preoperative CEA levels were associated with advanced or metastatic disease and thus poorer prognosis. Postoperatively, failure of CEA to return to normal was found to be indicative of residual or recurrent disease. However, measurement of CEA levels alone was not sufficient to improve survival rates. Two algorithms are proposed to guide investigation of patients with elevated CEA: one for patients with elevated CEA after CRC resection, and another for patients with de novo elevated CEA. CEA measurement has an important role in the investigation, management and follow-up of patients with colorectal cancer.

Association between <em>MDR1</em> polymorphisms and XELIRI and XELOX chemoresistance in Saudi patients with colorectal cancer

“…Therefore, genetic-based studies are crucial in identifying biomarkers related to geographical, economic and pathological factors in a given population with a variety of ethnic features. CEA a fetal glycoprotein that is considered to be a tumor marker that is widely used to clinically evaluate the responses of patients to treatment and tumor prognosis (20). The normal level of CEA is <2.5 ng/ml in adult non-smokers and ≤5 ng/ml in adult smokers (20).…”

“…CEA a fetal glycoprotein that is considered to be a tumor marker that is widely used to clinically evaluate the responses of patients to treatment and tumor prognosis (20). The normal level of CEA is <2.5 ng/ml in adult non-smokers and ≤5 ng/ml in adult smokers (20). Previous empirical studies and meta-analyses have found that measuring CEA levels can aid in monitoring chemotherapeutic responses in patients with CRC, particularly when imaging protocols are unsuitable for assessing these responses in clinical practice (27,28).…”

“…CEA a fetal glycoprotein that is considered to be a tumor marker that is widely used to clinically evaluate the responses of patients to treatment and tumor prognosis ( 20 ). The normal level of CEA is <2.5 ng/ml in adult non-smokers and ≤5 ng/ml in adult smokers ( 20 ).…”

“…To assess the association between the genetic variants of the patients with their drug responses, the genotype distribution and allele frequency of the two MDR1 SNPs were compared against the levels of CEA, which is a major CRC tumor marker used to determine patient response to treatment (20). CEA levels and follow-up CT scan imaging demonstrated that among the 62 patients, 36 were drug resistant (CEA level >3 ng/ml).…”

“…Patients at metastatic stages III and IV received a combination of the same doses of XELIRI and XELOX with bevacizumab (Roche Diagnostics) intravenously (5 mg/kg) every 2 weeks. Blood levels of carcinoembryonic antigen (CEA), a CRC tumor marker, were measured twice at Biochemistry lab in King Abdulaziz University Hospital using ARCHITECT CEA chemiluminescent assay (Abbott Pharmaceutical Co. Ltd.) and follow-up CT-scan imaging was performed following the completion of the chemotherapy cycles to assess the response of cancer cells to treatment with either XELIRI or XELOX (20). Based on the CEA level, the patients were divided into either drug-resistance (>3 ng/ml) or drug-response (<3 ng/ml).…”