hCG Tumor Marker
When your symptoms suggest gestational trophoblastic disease or germ cell tumors; to evaluate the effectiveness of treatment for these conditions; to monitor for recurrence
A blood sample drawn from a vein in your arm
Human chorionic gonadotropin (hCG) is a hormone produced by the placenta and normally is only present during pregnancy. Some abnormal tissues, tumors, and cancers, however, may also produce hCG, making the hCG test useful as a tumor marker. This test measures the amount of hCG in the blood.
An increased level of hCG is seen with gestational trophoblastic disease and some germ cell tumors (benign and cancerous). If hCG is increased with these conditions, then the hCG test can be used as a diagnostic and monitoring tool.
Gestational trophoblastic disease (GTD) is a group of tumor types that develop in a woman's uterus from the layer of cells that surrounds an embryo that creates the placenta during a normal pregnancy (trophoblasts) and produces hCG. GTD occurs at the beginning of pregnancy after an egg has been fertilized but instead of supporting the growth of a fetus, the cells form abnormal tissue masses. In most cases, the tumors are benign, but in a small percentage of people, they are cancerous. According to the American Cancer Society, GTD occurs about every 1 in 1,000 pregnancies. It can also sometimes occur after a normal pregnancy or after a miscarriage or abortion. The primary forms of GTD are:
- Hydatidiform mole – also called a "molar pregnancy," which may be complete (only tumor tissue) or partial (a mixture of tumor and fetal tissue but does not develop into a baby that can survive); these are usually benign but must be surgically removed.
- Invasive mole – a hydatidiform mole that grows into the uterus wall; it must be surgically removed and if GTD tissue remains, the condition can persist.
- Choriocarcinoma – a rare cancer that may develop from the GTD tumor tissue in about every 2 to 7 of 100,000 pregnancies; these cancers can grow quickly and spread to other parts of the body.
Note: With appropriate treatment, the cure rate for GTD is very high. For more on this, see the Related Links tab.
Germ cell tumors and cancers occur primarily in the ovaries and testicles but can also rarely develop in other locations such as the chest.
- Germ cell tumors can occur in the egg-producing cells of the ovaries and are more often seen in younger women (for more, see Ovarian Cancer).
- Germ cell tumors can affect cells within the testicles that make sperm and account for more than 90% of testicular cancers (for more, see Testicular Cancer).
Levels of hCG may also be elevated in other diseases such as liver, breast, lung, skin, and stomach cancers. Increased levels may also be seen in benign conditions such as cirrhosis, duodenal ulcer, inflammatory bowel disease, and marijuana use.
How is the sample collected for testing?
A blood sample is taken by needle from a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
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 lactase 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 a tumor or cancer is producing hCG, then the hCG test can be used to help detect and monitor tumor activity.
Gestational trophoblastic disease is a group of tumor types that develop in a woman's uterus. Germ cell tumors and cancers occur primarily in the ovaries and testicles but can also rarely develop in other locations such as the chest. For more on these conditions, see the "What is being tested?" section.
When is it ordered?
A quantitative hCG test may be ordered when a health practitioner suspects that a person may have gestational trophoblastic disease (GTD) or a germ cell tumor due to the person's clinical presentation and 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
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.
What does the test result mean?
In men and in non-pregnant women, the hCG level is normally undetectable.
A very high level of hCG may be seen in gestational trophoblastic disease (GTD) and the level may continue to rise past the first trimester if the woman is pregnant.
During treatment for GTD or a germ cell tumor, a falling hCG level generally indicates that the condition is responding to treatment, 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.
Is there anything else I should know?
There are reports of false-positive serum hCG results 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.
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 this type of testing.
Can gestational trophoblastic disease (GTD) be prevented?
No, other than not getting pregnant since GTD is associated with pregnancy. GTD can, however, be detected soon after conception in most cases and can be successfully treated. It is rare and most women will never have the condition.
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.
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). 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 Drugs of Abuse Testing.)
On This Site
Elsewhere On The Web
MedlinePlus Medical Encyclopedia: Gestational Trophoblastic Disease
American Cancer Society: What is gestational trophoblastic disease?
American Cancer Society: Can ovarian cancer be found early?
American Cancer Society: How is testicular cancer diagnosed?
National Cancer Institute: Ovarian Germ Cell Tumors
National Cancer Institute: General Information About Gestational Trophoblastic Disease
National Cancer Institute: General Information About Testicular Cancer
MedlinePlus Medical Encyclopedia: Hydatidiform mole