Gestational Trophoblastic Tumor Staging 

Updated: Dec 31, 2015
  • Author: from Memorial Sloan-Kettering - Elizabeth L Jewell, MD, MHSc; Chief Editor: from Memorial Sloan-Kettering - Yukio Sonoda, MD  more...
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Staging and Scoring for Gestational Trophoblastic Neoplasia

Gestational trophoblastic neoplasia (GTN) is staged by The American Joint Committee on Cancer (AJCC) and the Féderation Internationale de Gynécologie et d’Obstétrique (FIGO) based on the criteria below (see table 1). [1, 2] The FIGO staging and classification system is more commonly used, since lymph nodes are rarely evaluated in the staging of GTN.

Table 1. TNM Classification for Gestational Trophoblastic Neoplasia [1] (Open Table in a new window)

Primary tumor (T)
TNM category FIGO stage Surgical-pathologic findings
TX   Primary tumor cannot be assessed
T0   No evidence of primary tumor
T1 I Tumor confined to uterus
T2 II Tumor extends to other genital structures (ovary, tube, vagina, broad ligaments) by metastasis or direct extension
Distant metastasis (M)
TNM category FIGO stage Surgical-pathologic findings
M0   No distant metastasis
M1   Distant metastasis
M1a III GTN extends to the lungs with or without known genital metastases
M1b IV All other metastases

The World Health Organization (WHO) prognostic scoring system is important in the medical management of patients with complete hydatidiform moles, partial hydatidiform moles, and choriocarcinomas. [2] Therefore, the FIGO staging system incorporates a modified WHO prognostic scoring system.

The scores from the 8 risk factors are summed and incorporated into the FIGO stage, separated by a colon (eg, stage II:4, Stage IV:9). Scores of 0-6 are considered low risk. Scores of 7 and greater are considered high risk (see Table 2, below). [2] The modified WHO prognostic scoring system is not applicable to patients with placental-site trophoblastic disease (PSTT) or epithelioid trophoblastic tumor (ETT).

Table 2. Modified WHO Prognostic Scoring System as Adapted by FIGO [2] (Open Table in a new window)

Risk factor Score of 0 Score of 1 Score of 2 Score of 4
Age < 40y ≥40y
Antecedent pregnancy Mole Abortion Term
Interval months from index pregnancy < 4 4-6 7-12 >12
Pretreatment serum hCG* level < 103 103 -104 104 -105 >105
Largest tumor size (including uterus) < 3 cm 3-4 cm ≥5 cm
Site of metastases Lung Spleen, kidney Gastrointestinal system Liver, brain
Number of metastases 1-4 5-8 >8
Previous failed chemotherapy Single drug ≥2 drugs
*hCG = human chorionic gonadotropin