After the diagnosis of complete or partial hydatidiform mole is made or suspected, the uterine contents are removed by suctioning (called dilation and evacuation, D&E) Hysterectomy may be advisable in older patients who have completed childbearing to reduce the risk of malignancy. After the uterus is emptied, testing for human chorionic gonadotropin should be performed every week in order to determine if the molar pregnancy is malignant. If the molar pregnancy is benign the hormone level will become undetectable in 8-12 weeks. Hormone testing should be continued until three weekly negative levels are obtained, then followed by monthly tests for six months, after which pregnancy is permitted. During the six month follow-up it is important to avoid pregnancy. The use of oral contraceptives is safe.
A rise in the hormone level indicates that the molar pregnancy is malignant GTD (also called gestational trophoblastic neoplasia, GTN). More tests will be done to find out if the cancer has spread from the uterus to other parts of the body (called staging). Even if GTD has spread to other parts of the body it is still highly curable.
The stages of malignant GTD are:
Stage I The cancer has not spread from the uterus
Stage II The cancer has spread from the uterus to other structures in the pelvis
Stage III The cancer has spread to the lungs
Stage IV The cancer has spread to other organs
The treatment of malignant GTD depends on the stage and number of risk factors which determine the type of drugs that will most likely cure the disease. The factors that are characteristic of women who are likely to be cured by one or more single chemotherapy drugs (called low-risk malignant GTD) are:
- The last pregnancy was less than 4 months ago
- The level of hCG in the blood is low
- The cancer has not spread to the liver, brain and/or other distant organs
- The patient has not received chemotherapy treatments earlier
The risk factors of women who develop malignant GTD who are NOT likely to be cured by one or more single chemotherapy drugs and who require treatments containing multiple agents to effect cure (called high-risk malignant GTD) are:
- The last pregnancy was more than 4months ago
- The level of hCG in the blood is high
- The cancer has spread to the liver, brain and/or other distant organs
- The patient received chemotherapy earlier and the cancer did not go away
- The tumor began after completion of a normal pregnancy
Three kinds of treatment are used for malignant GTD: surgery (removing the cancer), chemotherapy (using drugs to kill the cancer) and radiation therapy (uses high energy x-rays to kill cancer cells and shrink tumors). The most common operation used for malignant GTD is hysterectomy, an operation to take out the uterus. Surgery may also be used to remove cancer involving the lungs and other organs which have not gone away with drug therapy.
Chemotherapy is the main treatment for malignant GTD and is generally highly effective. Chemotherapy uses drugs to kill cancer cells. It may be taken by pill, or by a needle in vein or muscle. It is called 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. Patients can preserve fertility and still be cured with chemotherapy even in the presence of widespread disease.
Radiation may infrequently be used in certain cases to treat cancer that has spread to other parts of the body, particularly the brain. 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).
Placental site trophoblastic tumors, unlike choriocarcinoma, are not very sensitive to chemotherapy. Since in most cases the tumor is localized to the uterus, hysterectomy is generally curative. When the disease spreads outside the uterus, high dose chemotherapy is used with some success.