Comparison of human chorionic gonadotropin regression in molar pregnancies and post-molar nonmetastatic gestational trophoblastic neoplasia.

The rate of regression of the beta subunit of human chorionic gonadotropin in patients successfully treated by single-agent chemotherapy with methotrexate (MTX) for postmolar nonmetastatic gestational trophoblastic neoplasia (NMGTN) has not previously been described. In 21 patients with NMGTN treated with MTX, the rate of regression was determined. Nineteen patients had a log-exponential disappearance of serum beta-hCG titers within 100 days. There was a 50% probability of a negative titer at 50 days. Two patients had plateauing titers within 63 days after therapy. There was no difference in beta-hCG disappearance whether MTX with citrovorum factor or MTX alone was administered. Also, the regression rate of beta-hCG titer in the treated patients was compared to 63 patients with spontaneous decline of titers postevacuation of trophoblastic disease. In the postevacuation group there was a 50% probability at 49 days of negative serum titers. All 63 patients had negative titers within 105 days after evacuation.