Gestational trophoblastic disease is a rare type of cancer in women in which cancer cells grow in the tissues that are formed following conception (the joining of sperm and egg). Gestational trophoblastic tumors start inside the uterus, the hollow, muscular, pear-shaped organ where a baby grows. This type of cancer occurs in women during the years when they are able to have children.

There are two types of tumors in gestational trophoblastic disease:

Hydatidiform mole - If a woman has a hydatidiform mole (also called a molar pregnancy), the sperm and egg cells have joined but do not develop into a baby in the uterus. Instead, the tissue that is formed resembles grape-like cysts. Hydatidiform mole does not spread outside of the uterus to other parts of the body. These tumors occur are detected in about 1 in 600 therapeutic abortions and 1 in 1,500 pregnancies.

Choriocarcinoma - With choriocarcinoma, the tumor may have started from a hydatidiform mole or from tissue that remains in the uterus following an abortion or delivery of a baby. Choriocarcinoma occurs in about 1 in 20,000–40,000 pregnancies. Choriocarcinoma can spread from the uterus to other parts of the body. A very rare type of gestational trophoblastic tumor starts in the uterus where the placenta was attached. This type of cancer is called placental-site trophoblastic disease.

How is gestational trophoblastic disease diagnosed?
Gestational trophoblastic disease is not always easy to detect. In its early stages, it may look like a normal pregnancy. Some women may have vaginal bleeding (not menstrual bleeding) and may not feel baby movement at the expected time.

If there are symptoms, a physician may use several tests to detect a gestational trophoblastic tumor. An internal (pelvic) examination is usually the first of these tests. The physician will feel for any lumps or abnormalities in the shape or size of the uterus. The physician may then do an ultrasound, a test that uses sound waves to find tumors. A blood test will also be done to look for high levels of a hormone called beta-HCG (beta human chorionic gonadotropin) which is present during normal pregnancy. If a woman is not pregnant and HCG is in the blood, it can be a sign of gestational trophoblastic disease.

Stages of gestational trophoblastic tumors
Once a gestational trophoblastic tumor has been found, more tests will be done to find out if the cancer has spread from inside the uterus to other parts of the body (staging). Knowing the stage of the disease helps plan treatment. The following stages are used for gestational trophoblastic disease:

Hydatidiform mole - Cancer is found only in the space inside the uterus. If the cancer is found in the muscle of the uterus, it is called an invasive mole (choriocarcinoma destruens).

Placental-site gestational trophoblastic tumors - Cancer is found in the place where the placenta was attached and in the muscle of the uterus.

Nonmetastatic - Cancer cells have grown inside the uterus from tissue remaining following treatment of a hydatidiform mole or following an abortion or delivery of a baby. Cancer has not spread outside the uterus.

Metastatic, good prognosis - Cancer cells have grown inside the uterus from tissue remaining following treatment of a hydatidiform mole or following an abortion or delivery of a baby. The cancer has spread from the uterus to other parts of the body. Metastatic gestational trophoblastic tumor has a good prognosis if all of the following are true:

• The last pregnancy was less than 4 months ago.
• The level of beta-HCG in the blood is low.
• Cancer has not spread to the liver or brain.
• The woman has not received chemotherapy earlier.

Metastatic, poor prognosis - Cancer cells have grown inside the uterus from tissue remaining following treatment of a hydatidiform mole or following an abortion or delivery of a baby. The cancer has spread from the uterus to other parts of the body.

Metastatic gestational trophoblastic tumor has a poor prognosis if any the following are true:

• The last pregnancy was more than 4 months ago.
• The level of beta-HCG in the blood is high.
• Cancer has spread to the liver or brain.
• The woman received chemotherapy earlier and the cancer did not go away.
• The tumor began after the completion of a normal pregnancy.

Recurrent
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the uterus or in another part of the body.

Treatment for gestational trophoblastic disease
The chance of recovery and choice of treatment depend on the type of gestational trophoblastic tumor, whether it has spread to other places, and the woman’s general state of health.

There are treatments for all women with gestational trophoblastic disease. Two kinds of treatment are used: surgery (taking out the cancer) and chemotherapy (using drugs to kill cancer cells). Radiation therapy (using high-energy x-rays to kill cancer cells) may be used in certain cases to treat cancer that has spread to other parts of the body.

Surgical Treatment - The physician may remove the cancer using one of the following operations:

• Dilation and curettage (D & C) with suction evacuation is stretching the opening of the uterus (the cervix) and removing the material inside the uterus with a small vacuum-like device. The walls of the uterus are then scraped gently to remove any material that may remain in the uterus. This is used only for hydatidiform mole pregnancies.
• Hysterectomy is an operation to take out the uterus. The ovaries usually are not removed in the treatment of this disease.
• Following surgery, your physician will perform blood tests to make sure the level of beta-HCG in the blood falls to normal levels. If the blood level of beta-HCG increases or does not go down to normal, more tests will be done to see whether the tumor has spread.

Chemotherapy uses drugs to kill cancer cells. It may be taken by pill or put into the body by a needle in a vein or muscle. It is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells outside the uterus. Chemotherapy may be given before or after surgery or alone.

Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes into the area where the cancer cells are found (internal radiation).

Treatment of gestational trophoblastic tumor depends on the stage of the disease, and the woman’s age and overall condition. Standard treatment may be considered because of its effectiveness in women in past studies, or participation in a clinical trial may be considered. Not all women are cured with standard therapy and some standard treatments may have more side effects than are desired. For these reasons, clinical trials are designed to find better ways to treat cancer patients and are based on the most up-to-date information.