Criteria for Initiating Chemotherapy in Patients after Evacuation of Hydatidiform Mole

Objectives: To evaluate the spontaneous regression curve of serum human chorionic gonadotropin (hCG) in patients with an uneventful course after evacuation of hydatidiform mole and to compare the criteria for initiating chemotherapy in patients after evacuation of mole. Methods: From 1986 to 2001, 608 patients were followed at our department after evacuation of mole. The spontaneous regression curves of serum hCG in 432 patients with an uneventful course were established. Results: After evacuation of mole, the titers of serum hCG decreased constantly, and 90% of patients with an uneventful course were within normal range within 16 weeks. In 432 patients with an uneventful course, the upper 95% confidence limit of serum hCG at 5, 8 and 20 weeks was 753.7, 422.9 and 14.8 mIU/ml, respectively. Moreover, 39 (9.0%) and 15 patients (3.5%) with an uneventful course might have been diagnosed with gestational trophoblastic tumor and received needless chemotherapy based on the normal regression curve established by the Japan Society of Obstetrics and Gynecology or the US criteria of 4 consecutive plateauing or rising hCG values, respectively. Conclusions: Our more selective criteria for initiating chemotherapy in patients after evacuation of mole, i.e. hCG of 10,000 mIU/ml at 5 weeks, 1,000 mIU/ml at 8 weeks and nondetectable levels at 24 weeks after evacuation of mole, may be safe and acceptable in the management of patients after evacuation of mole.