Staging and classification of gestational trophoblastic disease.

Many staging, classification and prognostic systems have been applied to persistent trophoblastic disease. Also terminology has differed across the world, together with criteria for treatment. Consequently it has been difficult to compare results from different centres and it is likely that some patients have been either under or over treated, resulting in increased chemoresistance or treatment toxicity, respectively. There is a need for globally agreed guidelines. This chapter addresses developments leading up to the recent publication of an internationally agreed staging/prognostic scoring system.