What are the key statistics about gestational trophoblastic disease?
Hydatidiform moles occur in about 1 pregnancy out of 1,000 in the United States and Europe. In very rare cases (less than 1%), a normal fetus can develop along with the hydatidiform mole.
In about 15% of cases, a hydatidiform mole will progress to become an invasive mole. Overall, invasive moles occur at an estimated rate of 1 pregnancy in 15,000.
Choriocarcinoma, a malignant form of gestational trophoblastic disease (GTD), is even less common, affecting around 2 to 7 of every 100,000 pregnancies in the United States. Like other forms of GTD, choriocarcinoma is more common in many Asian and African countries.
About 2% to 4% of hydatidiform moles progress to become choriocarcinoma. But only half (50%) of all gestational choriocarcinomas start off as molar pregnancies. About one-quarter (25%) of all choriocarcinomas develop in women who have a miscarriage (spontaneous abortion), intentional abortion, or tubal pregnancy (the fetus develops in the fallopian tube, rather than in the uterus). Another quarter (25%) develop after normal pregnancy and delivery.
Overall, gestational trophoblastic tumors account for less than 1% of female reproductive system cancers.
Cure rates depend on the type of GTD and its stage, as described in the section “Treatment of gestational trophoblastic disease by type and stage.”
Last Medical Review: 09/26/2012
Last Revised: 09/26/2012