What are the other Names for this Test? (Equivalent Terms)
- Alpha Feto-Globulin Tumor Marker Test
- Alpha Fetoprotein Level Tumor Marker Test
- Total AFP Tumor Marker Test
What is Alpha Feto-Protein (AFP) Tumor Marker Test? (Background Information)
- Alpha feto-protein (AFP) is a form of serum protein similar to albumin, the most abundant protein in blood. It is produced by a developing fetus in the liver, yolk sac, and the gastrointestinal tract
- The level of alpha feto-protein starts to decrease soon after birth and is very low in normal adults i.e., less than 10 ng/ml (nanogram per milliliter). However, the level of AFP may increase in adults, in the following cases:
- During pregnancy
- Liver diseases such as hepatitis and cirrhosis
- Certain malignancies, such as hepatocellular (liver) carcinoma, germ cell (non-seminoma) carcinoma of the testis, ovarian cancer, and cancers that spread (metastatic cancers) to the liver
- The levels of alpha fetoprotein may also be elevated sometimes with other malignancies, such as pancreatic cancer, gastric cancer, colon cancer, and lung cancer not associated with liver metastasis. In other words, an increased AFP level in these cancers may not indicate liver metastasis
- The Alpha Feto-Protein (AFP) Tumor Marker Test measures the amount of alpha fetoprotein in blood in both adults and children. Measuring the blood levels of AFP in suspicious cases helps in:
- Screening and early detection of cancer
- Monitoring cancer and its response to treatment
- Some healthcare providers may compare total alpha feto-protein levels to specific AFP-L3 levels, a variant of AFP. This may help in evaluating the risk of a future development of hepatocellular carcinoma in individuals at risk for the condition
It is important to note that alpha fetoprotein levels can be increased with tumor and non-tumor conditions. Thus, elevated AFP levels alone do not indicate the presence of malignancies.
What are the Clinical Indications for performing the Alpha Feto-Protein (AFP) Tumor Marker Test?
Clinical indicators for performing the Alpha Feto-Protein (AFP) Tumor Marker Test include:
- Suspicion of hepatocellular cancer (HCC, affecting the liver), or germ cell cancer of the testis, or ovarian cancer, based on clinical examination and/or radiological tests. Such testing would help in early diagnosis and treatment of the condition
- Monitoring of cancer recurrence (if any); alpha feto-protein levels may increase, if the cancer returns
- Monitoring effectiveness of the treatment provided; AFP levels decrease with effective treatment
- Additional tests for screening are required to confirm cancers in which the AFP levels are usually elevated
- Given their low specificity and sensitivity, the AFP Tumor Marker Test is generally not used as screening tool in detecting malignancies. The test is rather used as an indicator, in conjunction with other clinical findings and radiological results, to help diagnose various cancers
- Also, it is also important to note that in healthy individuals with normal immune system, the test is not recommended for cancer detection as a screening tool
How is the Specimen Collected for Alpha Feto-Protein (AFP) Tumor Marker Test?
Following is the specimen collection process for Alpha Feto-Protein (AFP) Tumor Marker Test:
Sample required: Blood
Process of obtaining blood sample in older children and adults:
- A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit)
- The site is cleaned with 70% alcohol in an outward spiral, away from the zone of needle insertion
- The needle cap is removed and is held in line with the vein, pulling the skin tight
- With a small and quick thrust, the vein is penetrated using the needle
- The required amount of blood sample is collected, by pulling the plunger of the syringe out slowly
- The wrap band is removed, gauze is placed on the collection site, and the needle is removed
- The blood is immediately transferred into the blood container, which has the appropriate preservative/clot activator/anti-coagulant
- The syringe and the needle are disposed into the appropriate “sharp container” for safe and hygienic disposal
- In newborns, infants, and younger children, the blood sample is drawn from the heel after making a small nick using a scalpel. This is called a heel stick
Preparation required: No special preparation is needed prior to the test.
What is the Significance of the Alpha Feto-Protein (AFP) Tumor Marker Test Result?
The significance of Alpha Feto-Protein (AFP) Tumor Marker Test is explained.
Increased levels of alpha fetoprotein:
- Increased levels of alpha fetoprotein in a (non-pregnant) adult or child may signify hepatocellular (liver) cancer, or cancer of the ovary, or metastatic tumors affecting the liver
- AFP may be also increased with certain testicular tumors such as yolk sac tumor of testis, embryonal carcinoma of testis, choriocarcinoma of testis, and mixed germ cell tumor of testis
- In patients, who have chronic liver disease, the levels may be elevated to about 100 ng/ml. This may result in a false positive result, causing unnecessary anxiety for cancer
- However, levels more than 500 ng/ml signifies the development of hepatocellular carcinoma, or germ cell tumor of the testis, or ovarian cancer
- If AFP levels rise in patients previously treated for cancer, it may signify a recurrence of the condition
- Alpha fetoprotein levels may not be significantly elevated in every case of cancer of the liver, ovary, or testis, since not all such cancers produce AFP
- If AFP levels are elevated prior to cancer treatment, then serial levels are obtained to monitor treatment effectiveness. With appropriate and effective treatment, the AFP levels are known to drop
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- Increased levels of total AFP and AFP-L3 in patients having chronic liver disease may point to the development of hepatocellular carcinoma (in future). In such cases, the cancer that develops may have a poor prognosis
- Individuals with high levels of both, total AFP and AFP-L3, in the absence of liver disease, may or may not develop cancer
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.