Gestational Trophoblastic Disease: Stage and Risk Grouping

Approved by the Cancer.Net Editorial Board, 11/2022

ON THIS PAGE: You will learn how doctors describe the disease’s growth or spread. This is called the stage. Use the menu to see other pages.


What is staging?

Staging is a way of describing where the tumor is located, if it is cancerous, if or where it has spread, and whether it is affecting other parts of the body.

Doctors use diagnostic tests to find out the tumor’s stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor recommend the best kind of treatment, and it can help predict a patient's prognosis, which is the chance of recovery. There are different stage descriptions for different types of tumors.

For gestational trophoblastic disease (GTD), the staging system developed by the International Federation of Obstetrics and Gynecology (Federation Internationale de Gynecologie et d'Obstetrique or FIGO) is used.

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FIGO anatomic staging

  • Stage I: Disease is only in the uterus.

  • Stage II: GTD extends outside the uterus but is limited to the genital structures.

  • Stage III: GTD extends to the lungs and may or may not involve the genital tract.

  • Stage IV: GTD has extended to other distant sites, called metastasis.

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World Health Organization (WHO) Risk Score as used by FIGO

FIGO staging includes a risk score developed by the WHO. This is because this prognostic risk score is helpful in building an effective treatment plan for each patient.

The table below shows how the risk score is determined. Each prognostic factor is assigned a score. Then, all of those scores from each prognostic factor are added together to calculate the WHO risk score.

  • Low risk is a score of 6 or less. People with a low-risk tumor have a good prognosis, even if cancer has spread, because treatment is usually very effective.

  • High risk is a score of 7 or more. People with a high-risk tumor may require more intense treatment even if the tumor has not spread.

Prognostic Factor






Younger than 40

40 or older

Previous pregnancy

Hydatidiform mole


Full-term pregnancy

Months since last pregnancy

Less than 4

4 to 6

7 to 12

More than 12

Pretreatment hCG (IU/mL)

Less than 10³

10³ to 104

Greater than 104 to 105

105 or more

Largest tumor size, including uterus

Less than 3 centimeters (cm)

3 to less than 5 cm

5 cm or more

Site of spread


Spleen or kidney

Gastrointestinal tract

Brain, liver

Number of tumors that have spread*


1 to 4

5 to 8

More than 8

Number of drugs used to treat the tumor that have not worked



1 drug

2 or more drugs

*For lung metastases, chest x-ray (not CT scan) is used to count the number of metastases.

The patient’s diagnosis is assigned to a stage group represented by a Roman numeral: I, II, III, and IV (1, 2, 3, and 4, respectively). Then, the sum of the prognostic factor scores is put after a colon. For example, stage II:4 or stage IV:9. Nearly every patient with GTD will be given a stage and score.

For people with PSTT/ETT, only the stage will be given. A risk factor score is not applicable in these cases.

Recurrent: Recurrent GTD is a tumor that has come back after treatment. If the tumor does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.

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Information about the GTD's stage will help the doctor recommend a specific treatment plan. The next section in this guide is Types of Treatment. Use the menu to choose a different section to read in this guide.