Gestational Trophoblastic Disease (GTD)
Learn more about gestational trophoblastic disease (GTD) and how it’s treated.
Overview
Gestational trophoblastic disease (GTD) is a group of rare tumours that begin in the uterus during or after pregnancy.
At the start of a normal pregnancy, cells called trophoblasts help the newly fertilized egg implant into the wall of the uterus. These cells then go on to develop into a large part of the placenta. In GTD, these trophoblasts develop abnormally and create tumours.
Most forms of GTD are noncancerous, but there are some forms that are cancerous. In many cases, patients who have had GTD can have healthy pregnancies after treatment.
Types of GTD
Hydatidiform moles (molar pregnancies)
Hydatidiform moles (also called molar pregnancies) are the most common type of GTD. They happen when abnormal tissue grows in your uterus instead of a placenta or a fetus. They are usually not cancer.
You may have a positive pregnancy test and experience pregnancy symptoms, but in most cases no baby is growing.
The following are the two types of hydatidiform moles.
Complete hydatidiform moles
These occur when the fertilized egg loses all the genetic material from the ovary and the genetic material from the sperm doubles instead. Instead of a fetus, abnormal tissue grows.
Partial hydatidiform moles
These occur when an egg is fertilized by two sperm, so the embryo cannot develop normally. These tumours have a lower risk of turning into cancer than complete hydatidiform moles.
Gestational trophoblastic neoplasia (GTN)
Gestational trophoblastic neoplasia (GTN) are almost always cancer. They include the following types.
Epithelioid trophoblastic tumours
These are very rare types of tumours that usually develop after a normal pregnancy. They are slow-growing and can go undiagnosed for a long time.
Gestational choriocarcinomas
These are aggressive tumours that usually develop after a hydatidiform mole, but can also happen after non-molar pregnancies.
Invasive moles
These happen when hydatidiform moles grow into the wall of the uterus. There is a small chance of invasive moles occurring after a molar pregnancy has been removed. Invasive moles are cancer but rarely grow outside of the uterus.
Placental site trophoblastic tumours
These are a very rare form of GTD that grow from specialized cells in the placenta after both molar and normal pregnancies. They rarely spread outside of the uterus.
Symptoms
Symptoms of GTD include any of the following:
- Vaginal bleeding
- Passing abnormal tissue from the vagina
- Pelvic pain
- Nausea
Having these symptoms does not necessarily mean that you have GTD. These are common symptoms for many conditions.
Diagnosis
If you have symptoms of GTD, your health-care provider can use a physical exam, ultrasound and blood tests to help confirm a diagnosis.
If your GTD is cancerous, additional imaging tests such as computed tomography (CT) scans, magnetic resonance imaging (MRI) and X-rays can be used to find out what stage of cancer you have.
Cancer staging
If cancer is found, the next step is determining the stage of cancer. Knowing the stage of your cancer helps your care team develop your treatment plan. Physicians determine the stage of your cancer based on the size and location of the tumour, whether cancer cells are in the lymph nodes and whether there are cancer cells in other parts of the body.
Treatment
If you have been diagnosed with GTD, your Cancer care team will discuss your treatment options with you. We will help you weigh the benefits of each treatment option against the possible risks and side effects.
The treatment options for GTD depend on the type of GTD and the stage of the disease.
A surgeon may remove the tumour with a procedure called a dilatation and curettage (D and C). In most cases, you can go home on the day of the procedure.
Depending on your specific needs, chemotherapy may be recommended in combination with the D and C.
In many cases, patients can have healthy pregnancies after treatment.