Gestational Trophoblastic Disease: Stages and Groups

Approved by the Cancer.Net Editorial Board, 07/2014

ON THIS PAGE: You will learn about how doctors describe the disease’s growth or spread. This is called the stage. To see other pages, use the menu on the side of your screen.

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 the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis, which is the chance of recovery. There are different stage descriptions for different types of tumors. For GTD, here is the staging system developed by the Federation Internationale de Gynecologie et d'Obstetrique, or FIGO.

FIGO Anatomic Staging

  • Stage I: Disease confined to the uterus
  • Stage II: GTD extends outside the uterus, but is limited to the genital structures
  • Stage III: GTD extends to the lungs, with or without known genital tract involvement
  • Stage IV: All other metastatic sites

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

The table below shows how the risk score staging factor is determined. Low risk is a score of 6 or less, and high risk is a score of 7 or more. Women with a low-risk tumor means the prognosis is good, even if cancer has spread, because treatment is usually very effective. Women with a high-risk tumor may require more intense treatment even if the tumor has not spread.

Risk Score

Prognostic Factor






Younger than 40

40 and/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

Greater than or equal to 10³ to 104

>104 to 105

Greater than or equal to 105

Largest tumor size, including uterus

Less than 3 cm

3 to <5 cm

Greater than or equal to 5 cm


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




Single drug

Two or more drugs


To stage and determine a risk factor score, a patient’s diagnosis is assigned to a stage as represented by a Roman numeral I, II, III and IV. This is then separated by a colon from the sum of all the actual risk factor scores expressed in Arabic numerals, such as Stage II:4 or Stage IV:9. This stage and score will be given for each patient. 

For people with PSTT/ETT only the stage will be given (risk factor score is not applicable).

