Prognosis
More than 80% of hydatidiform moles are benign. The outcome after treatment is usually excellent. Close follow-up is essential. Highly effective means of contraception are recommended to avoid pregnancy for at least 6 to 12 months.
In 10 to 15% of cases, hydatidiform moles may develop into invasive moles. This condition is named persistent trophoblastic disease (PTD). The moles may intrude so far into the uterine wall that hemorrhage or other complications develop. It is for this reason that a post-operative full abdominal and chest x-ray will often be requested.
In 2 to 3% of cases, hydatidiform moles may develop into choriocarcinoma, which is a malignant, rapidly-growing, and metastatic (spreading) form of cancer. Despite these factors which normally indicate a poor prognosis, the rate of cure after treatment with chemotherapy is high.
Over 90% of women with malignant, non-spreading cancer are able to survive and retain their ability to conceive and bear children. In those with metastatic (spreading) cancer, remission remains at 75 to 85%, although their childbearing ability is usually lost.
The prognosis of hydatidiform moles can be estimated by scoring systems such as the Modified WHO Prognostic Scoring System, wherein scores between 1 and 4 from various parameters are summed together:
| 0 | 1 | 2 | 4 | |
|---|---|---|---|---|
| Age | <40 | ≥40 | – | – |
| Antecedent pregnancy | mole | abortion | term | – |
| Interval months from index pregnancy | <4 | 4–6 | 7–12 | >12 |
| Pretreatment serum hCG (IU/L) | <103 | 103–104 | 104–105 | >105 |
| Largest tumor size (including uterus) | <3 | 3–4 cm | ≥5 cm | – |
| Site of metastases | lung | spleen, kidney | gastrointestinal | liver, brain |
| Number of metastases | – | 1–4 | 5–8 | >8 |
| Previous failed chemotherapy | – | – | single drug | ≥2 drugs |
Women with a score of 7 or greater are considered at high risk.
Read more about this topic: Hydatidiform Mole