Prognostic significance of the new placental proteins in trophoblastic disease.

Circulating levels of four specific placental proteins, human chorionic gonadotrophin (hCG), Schwangerschafts protein 1 (SP1), placental protein 5 (PP5) and pregnancy-associated plasma protein A (PAPP-A), were measured in 31 patients with hydatidiform mole before treatment. Seven patients subsequently developed clinical choriocarcinoma and three of them had pulmonary metastases. The estimations of hCG, PP5 and PAPP-A levels were found to be of no value in the prediction of malignant sequelae. Levels of SP1 greater than or equal to 16.5 i.u./l were associated with a higher incidence of subsequent malignant disease (P less than 0.05), the risk being at least nine times greater in these patients. The predictive value of high levels of SP1 was 35%, the specificity 45.8% and sensitivity 100%.