Management of gestational trophoblastic diseases in Japan--a review.

In Japan we have a standardized protocol for the management of gestational trophoblastic diseases issued by the Japan Society of Obstetrics & Gynecology in 1988. Hydatidiform moles should be treated by evacuating the uterus. Patients must then be followed up until serial weekly serum hCG titres fall to undetectable levels. Our hCG regression curve post-evacuation is quite useful for the detection of persistent trophoblastic diseases. Persistent trophoblastic diseases develop in about 10-15 per cent of patients after molar evacuation in Japan. We classify persistent trophoblastic diseases into three groups: (1) post-molar persistent hCG; (2) invasive mole or metastatic moles; and (3) choriocarcinoma. Investigations into any possible metastases are carried out as soon as possible in affected patients. Post-molar persistent hCG presents no focus or histological findings except persistent elevated hCG, although single agent chemotherapy is required. In the other two groups with focus, it is very difficult to get histological specimens to make accurate diagnoses unless surgery is done. For the selection of the most appropriate chemotherapy, what we call a 'Diagnostic Score' is applied to differentiate choriocarcinoma from invasive moles or metastatic moles clinically in patients falling into these two groups. This unique 'Diagnostic Score' for the detection of choriocarcinoma plays an important role in initial management in our protocol.