Persistent trophoblastic disease and choriocarcinoma are very rare pregnancy-related tumours known as gestational trophoblastic tumours (GTTs).
Persistent trophoblastic disease
About one in 750 pregnancies are found to be a molar pregnancy, where the foetus and placenta do not form properly and a baby does not usually develop. This typically results in a miscarriage (the loss of the pregnancy).
In a minority of molar pregnancies, the abnormal tissue is not fully removed during the miscarriage or following original gynaecological treatment. The remaining molar tissue can grow into the lining of the womb and, like a cancer, can spread to other areas of the body.
This is known as persistent trophoblastic disease. Vaginal bleeding is the most common symptom of persistent trophoblastic disease.
Further specialist treatment for persistent trophoblastic disease is needed to ensure that all of the remaining molar tissue is destroyed.
You may also need to have chemotherapy (powerful cancer-killing medication) as part of your treatment.
Choriocarcinoma is a very rare type of cancer that occurs in around one in 50,000 pregnancies. In the UK, it affects less than 20 women each year.
Choriocarcinoma can develop if the cells left behind after a pregnancy become cancerous. This can happen after any pregnancy, but it is more common following molar pregnancies. It can sometimes occur several months, or even years, after a pregnancy.
Although choriocarcinoma starts in the womb, it can spread to other parts of the body, including the lungs. If it spreads to your lungs, you may have symptoms such as coughing, difficulty breathing and chest pain.
If choriocarcinoma spreads to your abdomen, you may experience abdominal pain. If it spreads to your vagina, you may have heavy bleeding and a lump (nodule) may develop on your vagina.
Both persistent trophoblastic disease and choriocarcinoma are very rare. If you have had a molar pregnancy, you will be monitored closely in case you develop either of these conditions.
If you have had a complete molar pregnancy, you have about a one in 10 chance of developing either persistent trophoblastic disease or choriocarcinoma. If you have had a partial molar pregnancy, the risk is around one in 200.
Overall, the outlook for persistent trophoblastic disease and choriocarcinoma is excellent, and 98-100% of women who develop a GTT are cured. However, the outlook for individual cases will depend on the individual's circumstances.