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) systems, 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. [3]
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 |
– |
Months since 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 |
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Tables
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 |
Risk factor |
Score of 0 |
Score of 1 |
Score of 2 |
Score of 4 |
Age |
< 40y |
≥40y |
– |
– |
Antecedent pregnancy |
Mole |
Abortion |
Term |
– |
Months since 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 |
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