see also:

• neoplasia / cancer / tumours

• Elevated CEA levels are more common in smokers and in patients with inflammatory conditions but rarely exceed 10 ng/mL
• While mainly used as a tumour marker for colorectal cancer (bowel cancer), it may also be raised in other tumours such as:
  • lung cancer
  • breast cancer
  • other GIT or gynaecologic tumours
• the most frequent indicator used to detect recurrence in asymptomatic patients and currently is the most cost-effective test for the preclinical detection of resectable colorectal carcinoma disease
• Serial CEA measurements can detect recurrent colorectal cancer (bowel cancer) with a sensitivity of approximately 80%, a specificity of approximately 70%, and can provide a lead time of approximately 5 months.¹⁾
• is most useful for the early detection of liver metastasis in patients with diagnosed colorectal cancer
• but is of little use in detecting early colorectal cancer:
  • only 4% of stage 1 cases have a raised CEA, whereas 25%, 44%, and 65% of patients with stage II, III, and IV disease, respectively, had abnormal levels ²⁾
  • At a threshold of >5 ng ml−1 the sensitivities for detecting CRC up to 1 and 4 years before clinical presentation were 25% and 13%, respectively, at 95% specificity. At a threshold of >2.5 ng ml−1, sensitivities were 57.5% and 38.4%, respectively, with specificities of 81% and 83.5%³⁾

• mainly used as a marker for ovarian tumours as:
  • 75-85% of women with epithelial ovarian cancer will have a raised level and a decreasing level indicates therapy is being effective
  • in patients with a pelvic mass, a level > 65 units/mL is associated with a malignancy in 90% of cases
• it is a poor screening marker for colorectal cancer (bowel cancer)
• false positive raised levels may occur in:
  • pregnancy
  • endometriosis
  • uterine fibroids
  • pancreatitis
  • normal menstruation
  • pelvic inflammatory disease
  • cirrhosis

• mainly used for pancreatic cancer but also for gynaecologic malignancies
• at least 5% of the population is unable to produce the CA 19-9 antigen
• performance for pancreatic cancer depends upon cutoff level
  • at levels above 37 units/mL, sensitivity of 81% (68%-93%), a specificity of 90% (76%-100%), a PPV of 72%, and a NPV of 96%
  • at levels greater than 1000 U/mL, sensitivity is 41%, specificity is 99.8%, PPV is 97%, and NPV is 89%.⁴⁾
• may also be raised due to:
  • Biliary tract obstruction
  • ascending cholangitis
  • inflammatory bowel disease (IBD)
  • pancreatitis
  • cirrhosis
  • Cystic fibrosis
  • Thyroid disease
  • other tumours such as bile duct cancers, colorectal cancer (bowel cancer), stomach cancer, ovarian tumours, hepatocellular carcinoma, oesophageal cancer

• marker for trophoblastic disease
• obviously this is also raised in pregnancy