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tumour_markers

tumour markers

Carcinoembryonic antigen (CEA)

  • 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:
  • 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)

CA-125

  • 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

CA 19.9

HCG

  • marker for trophoblastic disease
  • obviously this is also raised in pregnancy
tumour_markers.txt · Last modified: 2018/02/02 13:51 by 127.0.0.1

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