Gestational trophoblastic disease is not staged but is divided into non-metastatic or metastatic classes. Non-metastatic choriocarcinoma is defined as having no disease outside the uterus and has a survival rate of 100 percent. Metastatic choriocarcinoma is further divided into low-risk (good prognosis) and high-risk (poor prognosis) based on several factors.
Increasingly, prognosis or outcome is determined according to a scoring system devised by the World Health Organization. Patients are classified into low-, intermediate- and high-risk groups and are treated accordingly.
