Persistent trophoblastic disease and choriocarcinoma are very rare pregnancy-related tumours known as gestational trophoblastic tumours (GTTs).
Persistent trophoblastic disease
In the UK, about 1 in 600 pregnancies each year 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 dilatation and curettage (D&C) and loss of the pregnancy (miscarriage).
In most molar pregnancies, any remaining abnormal tissue in the womb spontaneously dies off. But in a small proportion of women, the tissue can remain and grow further into the lining of the womb and, like a cancer, 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 make sure that all of the remaining molar tissue is destroyed.
In England, there are two specialist centres for treating the condition – Charing Cross Hospital in London and Weston Park Hospital in Sheffield.
You may also need to have powerful cancer-killing medicine (chemotherapy) as part of your treatment.
Choriocarcinoma is a very rare type of cancer that occurs in around 1 in 50,000 pregnancies. It affects less than 20 women each year in the UK.
Choriocarcinoma can develop if the cells left behind after a pregnancy become cancerous. This can happen after any pregnancy, but it is more likely after molar pregnancies. It can occur several months, or even years, after a pregnancy.
Although choriocarcinoma starts in the womb, it can spread to other parts of the body – most commonly, 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. If it spreads to your brain, it may cause headaches or seizures.
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 1 in 10 chance of developing either persistent trophoblastic disease or choriocarcinoma. If you have had a partial molar pregnancy, the risk is around 1 in 100.
Overall, the outlook for persistent trophoblastic disease and choriocarcinoma is excellent, and 98-100% of women who develop a gestational trophoblastic cancer are cured. However, the outlook for each case will depend on the individual's personal circumstances.
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What is cancer?
The body is made up of millions of different types of cells. Cancer occurs when cells multiply in an abnormal way.
When cancer affects organs and solid tissues, it causes a growth (tumour) to form. Cancer can occur in any part of the body where the cells multiply abnormally.
Read more about cancer.