Alpha Fetoprotein (AFP)

Alpha fetoprotein is present in the tissues and plasma of the foetus. Its concentration falls rapidly after birth but minute amounts can still be detected in plasma from adults. Pregnant women have raised levels of plasma AFP. Great increases in AFP occur in patients with hepatocellular carcinoma. Increases in plasma AFP in association with other malignant tumours such as gonadal, gastric, pancreatic and biliary tract neoplasms can also be detected. Lesser elevations may be found in non-neoplastic disease associated with liver cell regeneration.

Use of Test: Detection and monitoring of hepatocellular carcinoma and germ cell tumours, particularly for recurrence after treatment.

CA 125

CA 125 is a glycoprotein. It is a marker for serious carcinoma especially carcinoma of the ovary, but elevations are also seen in peritoneal disease of any cause.

Use of Test: The test should not be used as either screening or diagnostic test for malignancy. It may be used for monitoring effectiveness of therapy in patients with a malignancy that has been shown to produce  this marker.

CA 19-9

CA 19-9 is a marker for gastrointestinal malignancy, especially carcinoma of the pancreas.

Use of Test: The test should not be used as either screening or diagnostic test for malignancy. It may be used for monitoring effectiveness of therapy in patients with a malignancy that has been shown to produce  this marker.

Carcinoembryonic Antigen (CEA)

Slight increases may be seen in smokers and in patients with inflammatory bowel disease. It may be increased in patients with other carcinomas (lung, liver, pancreas). Increasing levels in patients with a history of colorectal or breast adenocarcinoma suggests local recurrence or metastatic disease.

Use of Test: Not sufficiently sensitive or specific to be used as a screening test for malignant disease. Can be used to detect recurrence of colonic adenocarcinoma and breast carcinoma following resection.

Prostate Specific Antigen (PSA)

Prostate specific antigen is localized in both normal prostatic epithelial cells and prostatic carcinoma cells. Serum PSA is markedly elevated in prostatic carcinoma. However increased levels are also seen in benign prostatic hypertrophy, prostatitis, prostatic ischemia and/or infarction and acute renal failure. Normal levels do not exclude prostatic carcinoma.

Use of Test: Diagnosis and monitoring the course of prostatic carcinoma. It is not recommended as a screening test for carcinoma of the prostate.

EBV EA+EBNA-1 IgA

Epstein-Barr virus (EBV), a human herpes virus, is a major aetiologic factor in a number of human diseases, including infectious mononucleosis, Burkitt’s lymphoma and nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant tumor which occurs among the Chinese living in this region. Its poor prognosis is due to the late stage at which the disease is detected. Therefore, early diagnosis is important.

Studies show that sera from NPC patients have high titers of EBV specific antibodies. Recently an ELISA method has been developed to detect the presence of IgA antibodies to the EB early antigen (EA) and the EB nuclear antigen-1 (EBNA-1).