TUMOUR MARKERS (CA 125, CA 19.9, CA 15.3, MSA, CA 549) - serum

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Specimen: 5 mL blood in plain tube.

Method: Immunoassay.

Reference Interval: Depends on marker and method.

Application: The tests should not be used as either screening or diagnostic tests for malignancy. They may be used to monitor effectiveness of therapy in patients with a malignancy that has been shown to produce the marker. CA 125 is a marker for serous carcinoma, esp carcinoma of the ovary, but elevations are also seen in peritoneal disease of any cause; CA 19.9 is a marker for gastrointestinal malignancy, esp carcinoma of the pancreas; CA 15.3, MSA and CA 549 are markers for breast cancer, which have only limited utility in monitoring disease. See also CARCINOEMBRYONIC ANTIGEN , ALPHA FETOPROTEIN , NEURONE SPECIFIC ENOLASE , PROSTATE SPECIFIC ANTIGEN .

Interpretation: Persistence of an increased level after treatment indicates a significant amount of residual tumour. Decrease to a normal level after treatment may mean eradication of the tumour or persistence of only small amounts of tumour; subsequent elevation indicates regrowth of the tumour. Lesser elevations may be found in some non-malignant conditions.

Reference: Jacobs I and Bast RC. Hum Reprod 1989; 4: 1-12. Sell S. Clin Lab Med 1990; 10: 27-31.

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