To help diagnose and monitor gestational trophoblastic disease or germ cell tumors
hCG Tumor Marker
hCG Tumor Marker
Also Known As
Quantitative hCG
Beta hCG
Total hCG
Total beta hCG
Intact hCG
Formal Name
Human Chorionic Gonadotropin, quantitative
This article was last reviewed
on
This article waslast modified
on November 28, 2018.
At a Glance
Why Get Tested?
When To Get Tested?
When your symptoms suggest gestational trophoblastic disease or germ cell tumors; to evaluate the effectiveness of treatment for these conditions; to monitor for recurrence
Sample Required?
A blood sample drawn from a vein
Test Preparation Needed?
None
Accordion Title
Common Questions
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How is it used?
Quantitative human chorionic gonadotropin (hCG) testing, often called beta hCG (βhCG), measures the amount of hCG present in the blood. It may be used to help diagnose gestational trophoblastic disease (GTD) or, with other tests such as AFP and lactate dehydrogenase, to help diagnose germ cell tumors.
Since hCG is not normally present in men or non-pregnant women, it is useful as a tumor marker. If the tumor or cancer is producing hCG, then the hCG test can be used to help detect and monitor tumor activity.
When testing hCG as a tumor marker, unlike detecting pregnancy, it is important to measure the intact (alpha + beta subunits) form of hCG. There may be some benefit to also measuring the beta-subunit of hCG in certain tumors, and different labs will detect intact and βhCG differently. For this reason, it is very important to continue to use the same lab when monitoring GTD or germ cell tumors.
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When is it ordered?
A quantitative hCG test may be ordered when a healthcare practitioner suspects that a person may have gestational trophoblastic disease (GTD) or a germ cell tumor due to the person's clinical presentation, signs and symptoms.
In women, signs and symptoms of GTD may include:
- Vaginal bleeding during pregnancy
- Fatigue related to anemia (if blood loss is significant)
- Abdominal swelling that may happen more rapidly than with a normal pregnancy
- Pre-eclampsia early in the pregnancy
- Nausea, vomiting that may be more severe than with a normal pregnancy
- A positive pregnancy test (qualitative hCG) but no fetus is seen on ultrasound
- A uterus that remains enlarged after a pregnancy
Signs and symptoms of a germ cell tumor in women and men are similar to those of ovarian cancer and testicular cancer, respectively.
If a person is diagnosed with one of these conditions and the hCG is initially elevated, then the test will be ordered at intervals to monitor the effectiveness of treatment and to detect tumor recurrence.
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What does the test result mean?
In men and in non-pregnant women, the hCG level is normally undetectable.
When the test is used as a tumor marker, an elevated hCG level may mean that an individual has a germ cell tumor or gestational trophoblastic disease (GTD).
A high level of hCG occurs in both GTD and normal pregnancy. However, hCG rises at a constant and predictable rate, doubling approximately every 36-48 hours in early normal pregnancy. Levels of hCG in GTD show altered rates of production and, paired with imaging such as ultrasound, can identify abnormalities in the pregnancy requiring intervention. Alternatively, the hCG levels may be much higher than expected in normal pregnancy or not show the expected decrease after pregnancy or abortion/miscarriage.
During treatment for GTD or a germ cell tumor, a falling hCG level generally indicates that the condition is responding to treatment (approximately 50% decrease expected every 1.5 days), while persistent or rising levels may indicate that it is not responding to therapy. An increased hCG level after treatment may indicate a recurrence of disease.
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Is there anything else I should know?
False-positive serum hCG results may occur due to the presence of certain drugs such as anticonvulsants, antiparkinsonian agents, hypnotics, and tranquilizers that may interfere with the test. In addition, certain types of antibodies that may be present in some individuals and fragments of the hCG molecule, if present, can also interfere with test results. Generally, if results are questionable, they may be confirmed by testing with a different method.
Rarely, an hCG test may be ordered to help diagnose and monitor tumors and cancers other than GTD or germ cell tumors.
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Can urine be tested instead of blood?
If hCG is elevated in the blood, then it will be elevated in the urine, but the results are not interchangeable. Blood is the preferred sample for tumor testing.
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Can gestational trophoblastic disease (GTD) be prevented?
No. Other than to avoid becoming pregnant, GTD is not preventable since GTD is associated with pregnancy. However, since it is rare, most women will never have the condition. Since GTD can be detected soon after conception in most cases and successfully treated, it is rarely considered a significant cause to avoid pregnancy.
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Can I have a normal pregnancy after having GTD?
Yes, in most cases, although you will be at a higher risk of having GTD again. After treatment for GTD, you will need to wait for a period of time as advised by your healthcare provider before becoming pregnant again.
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I heard that some athletes may be tested for hCG. Why is that?
Some athletes, including professional and international athletes, must submit to tests that detect steroids and other performance-enhancing substances. These athletes are often tested throughout their careers to ensure that no 'doping' occurs. Urine tests can detect about 200 compounds, including steroids and other anabolic substances, erythropoietin, and substances that cause false-negative results (masking agents) to hide illicit substance use. Sports organizations specify which compounds they might be looking for by doing a complete screen.
Some athletes who use steroids take beta-hCG to reverse shrinking of their testicles, which can be a side effect of steroids. Thus, some athletes may be tested for hCG to help identify steroid use. (For more on this, see the article on Drug Abuse Testing.)