Gestational trophoblastic disease (GTD) is a group of rare diseases in which abnormal trophoblast cells grow inside the uterus after conception.
In gestational trophoblastic disease (GTD), a tumor develops inside the uterus from tissue that forms after conception (the joining of sperm and egg). This tissue is made of trophoblast cells and normally surrounds the fertilized egg in the uterus. Trophoblast cells help connect the fertilized egg to the wall of the uterus and form part of the placenta (the organ that passes nutrients from the mother to the fetus).
Sometimes there is a problem with the fertilized egg and trophoblast cells. Instead of a healthy fetus developing, a tumor forms. Until there are signs or symptoms of the tumor, the pregnancy will seem like a normal pregnancy.
Most GTD is benign (not cancer) and does not spread, but some types become malignant (cancer) and spread to nearby tissues or distant parts of the body.
Gestational trophoblastic disease (GTD) is a general term that includes different types of disease:
Hydatidiform mole (HM) is the most common type of GTD.
HMs are slow-growing tumors that look like sacs of fluid. An HM is also called a molar pregnancy. The cause of hydatidiform moles is not known.
HMs may be complete or partial:
Most hydatidiform moles are benign, but they sometimes become cancer. Having one or more of the following risk factors increases the risk that a hydatidiform mole will become cancer:
Gestational trophoblastic neoplasia (GTN) is a type of gestational trophoblastic disease (GTD) that is almost always malignant.
Gestational trophoblastic neoplasia (GTN) includes the following:
Invasive moles are made up of trophoblast cells that grow into the muscle layer of the uterus. Invasive moles are more likely to grow and spread than a hydatidiform mole. Rarely, a complete or partial HM may become an invasive mole. Sometimes an invasive mole will disappear without treatment.
A choriocarcinoma is a malignant tumor that forms from trophoblast cells and spreads to the muscle layer of the uterus and nearby blood vessels. It may also spread to other parts of the body, such as the brain, lungs, liver, kidney, spleen, intestines, pelvis, or vagina. A choriocarcinoma is more likely to form in women who have had any of the following:
Placental-site trophoblastic tumors
A placental-site trophoblastic tumor (PSTT) is a rare type of gestational trophoblastic neoplasia that forms where the placenta attaches to the uterus. The tumor forms from trophoblast cells and spreads into the muscle of the uterus and into blood vessels. It may also spread to the lungs, pelvis, or lymph nodes. A PSTT grows very slowly and signs or symptoms may appear months or years after a normal pregnancy.
Epithelioid trophoblastic tumors
An epithelioid trophoblastic tumor (ETT) is a very rare type of gestational trophoblastic neoplasia that may be benign or malignant. When the tumor is malignant, it may spread to the lungs.
Age and a previous molar pregnancy affect the risk of GTD.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. Talk to your doctor if you think you may be at risk. Risk factors for GTD include the following:
Tests that examine the uterus are used to detect (find) and diagnose gestational trophoblastic disease.
The following tests and procedures may be used:
Signs of GTD include abnormal vaginal bleeding and a uterus that is larger than normal.
These and other signs and symptoms may be caused by gestational trophoblastic disease or by other conditions. Check with your doctor if you have any of the following:
GTD sometimes causes an overactive thyroid. Signs and symptoms of an overactive thyroid include the following:
There are different types of treatment for patients with gestational trophoblastic disease.
Different types of treatment are available for patients with gestational trophoblastic disease. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI website. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.
Three types of standard treatment are used:
The doctor may remove the cancer using one of the following operations:
Dilatation and curettage (D&C) with suction evacuation: A surgical procedure to remove abnormal tissue and parts of the inner lining of the uterus. The cervix is dilated and the material inside the uterus is removed with a small vacuum-like device. The walls of the uterus are then gently scraped with a curette (spoon-shaped instrument) to remove any material that may remain in the uterus. This procedure may be used for molar pregnancies.
Hysterectomy: Surgery to remove the uterus, and sometimes the cervix. If the uterus and cervix are taken out through the vagina, the operation is called a vaginal hysterectomy. If the uterus and cervix are taken out through a large incision (cut) in the abdomen, the operation is called a total abdominal hysterectomy. If the uterus and cervix are taken out through a small incision (cut) in the abdomen using a laparoscope, the operation is called a total laparoscopic hysterectomy.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated, or whether the tumor is low-risk or high-risk.
Combination chemotherapy is treatment using more than one anticancer drug.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy after surgery to kill any tumor cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.
See Drugs Approved for Gestational Trophoblastic Disease for more information.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type of cancer being treated.
New types of treatment are being tested in clinical trials.
Information about ongoing clinical trials is available from the NCI website.
Patients may want to think about taking part in a clinical trial.
For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.
Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
Patients can enter clinical trials before, during, or after starting their cancer treatment.
Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.
Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's listing of clinical trials.
Follow-up tests may be needed.
Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.
Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.
Blood levels of beta human chorionic gonadotropin (β-hCG) will be checked for up to 6 months after treatment has ended. This is because a β-hCG level that is higher than normal may mean that the tumor has not responded to treatment or it has become cancer.