Diseases Treated

Chemotherapy for molar pregnancy

Why is chemotherapy used in the high risk patient?

At the time of evacuation of a molar pregnancy it is generally impossible to remove all the abnormal tissue since some of it is microscopic and superficially invades the uterine wall. In most instances the tissue that is left behind following evacuation is destroyed by the body's own defense mechanism. This leads to a progressive drop in the hCG level to normal. In the remaining women, however, potentially malignant tumor tissue remains in the uterus and can either deeply invade the uterine wall causing hemorrhage or spread beyond the uterus to one or more vital organs. We have found that patients with high risk molar pregnancy run a 40 percent risk of developing persistent disease in the uterine wall (nonmetastatic) or spread to other parts of the body (metastatic). Only 4 percent of patients in the low risk category experience the problem of persistent disease. If chemotherapy is given at the time of evacuation, then the incidence of persistent disease in the high risk patient is reduced. Furthermore, treatment with chemotherapy prevents the women from developing metastatic disease.

Chemotherapy

Drugs used for the prophylactic treatment of patients with molar pregnancy may be either a drug called methotrexate and its antidote Citrovorum Factor or a drug called Actinomycin-D.

Methotrexate

Methotrexate has been used for over 40 years as an anti-tumor agent. When given alone it can cause toxic side effects such a hair loss, sore mouth, fever and skin rash. However, we administer this drug with an antidote (Citrovorum factor) so that side effects do not occur. Furthermore, there does not appear to be any effect on the ovaries or future childbearing. You may be given Methotrexate therapy one of two ways:

• Intramuscularly. Methotrexate is given intravenously over 12 hours at a dose calculated for your particular height and weight. You will receive injections or oral doses of the antidote, Citrovorum Factor, every 12 hours for four doses.
• Intravenously. Methotrexate is given intravenously over 12 hours at a dose calculated for your particular height and weight. You will receive injections or oral doses of the antidote, Citrovorum Factor, every 12 hours for four doses.

Actinomycin-D

In some patients, Methotrexate cannot be used because of temporary abnormalities in liver function due to transfusions or recent pregnancy. When this situation is present a drug called Actinomycin-D is used. This drug is usually given intravenously once a day for five days, generally at night before bedtime. Administration takes about 10 minutes and then the IV is removed.