WHO scoring system based on prognostic factors
| WHO prognostic factor | First assessment | Second assessment |
| Age | 0 | 0 |
| Antecedent pregnancy | 1 | 1 |
| Interval from index pregnancy, months | 0 | 1 |
| Pretreatment hCG mIU/mL | 1 | 4 |
| Largest tumor size including uterus, cm | 2 | 2 |
| Site of metastases including uterus | – | – |
| Number of metastases identified | – | – |
| Previous failed chemotherapy | – | 2 |
| Total score | 4 | 10 |
hCG, human chorionic gonadotropin.