Measurement of alpha-fetoprotein (or alpha-fetal globulin, AFP) as a cancer marker is mainly used in the investigation of testicular cancer, ovarian cancers, and hepatocellular carcinomas.
Αlpha-fetoprotein, an albumin-like glycoprotein, has a molecular weight of 70,000 daltons and is normally formed by the embryonic sac and embryonic gastrointestinal tract as well as various cancerous tissues, such as hepatocellular carcinoma, hepatoblastoma, and non-seminomas of ovarian and testicular germ cells. Most studies report elevated AFP concentrations in 70% of patients with hepatocellular carcinoma and in 50%-70% of patients with non-seminal testicular tumors. No correlation has so far been shown between AFP concentration and tumor size, stage, or degree of malignancy.
Elevated concentrations of AFP have also been found in patients with benign hepatic disease (viral hepatitis, cirrhosis), gastrointestinal tract tumors, and ataxia-telangiectasia.
Αlpha-fetoprotein is increased during pregnancy.
Μeasurement of alpha-fetoprotein is mainly used to check for any neural tube defects in the fetus, such as spina bifida and anencephaly. The examination, which takes place between the 15th and 20th weeks of pregnancy, is not totally diagnostic for the existence of genetic abnormalities. However, if alpha-fetoprotein is abnormally high, additional tests including ultrasound and amniotic fluid screening for AFP are necessary. Nowadays, the test for alpha-fetoprotein is combined with the measurement of free estriol and chorionic gonadotropin. The combination of these three tests is known as the "triple test" or "alpha test". Measurement of these three molecules provides information on neural tube abnormalities, trisomy 18, and trisomy 21 (Down syndrome). Exact fetal age is necessary for the accuracy of the test because the levels of the measured factors vary with the age of the pregnancy. The most accurate method for estimating gestational age is ultrasound and only if not available, the last menstrual period is used to calculate gestational age.
What do Pathological Rates mean?
- Increase: Biliary cirrhosis, multiple pregnancy, fetal distress, fetal neural tube deficiency, breast cancer, colon cancer, stomach cancer, liver cancer, hepatitis, lung cancer, pancreatic cancer, kidney cancer, testicular cancer.
- Reduction: Down syndrome, fetal death.
Important Note
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.
