Objective: To identify clinical factors associated with requiring more than a single course of Methotrexate (MTX) to achieve remission among women with low-risk postmolar gestational trophoblastic neoplasia (GTN).
Methods: We studied 150 women with persistent GTN after diagnosis of complete (n=110) or partial mole (n=40) to identify possible predictors of requiring additional treatment after a single treatment of methotrexate (MTX). All women had low-risk disease using FIGO and WHO scoring systems.
Results: Seventy women (47%) required additional courses of chemotherapy, of whom 45 (64%) received chemotherapy other than MTX. Multivariate analysis revealed that complete mole histology, presence of metastasis, single day MTX infusion and any increase in serum beta human chorionic gonadotropin (beta-hCG) level 1 week after MTX therapy were independent predictors of requiring additional MTX or alternative chemotherapy. Dilatation and curettage (D+C) within 1 week after the diagnosis of persistence did not affect future chemotherapy requirements (p>0.64). Following complete mole, beta-hCG levels >2000 mIU/mL at 1 week post MTX were associated with a 89% risk of additional cycles chemotherapy including MTX and a 65% risk of alternative chemotherapy.
Conclusions: Metastatic disease, MTX infusion protocol and complete mole histology were independently associated with the need for additional chemotherapy after an initial course of MTX for women with low risk GTN. D+C at persistence did not alter the chemotherapy requirement. Elevated beta-hCG level at 1 week after the initial course of MTX was also an independent factor predicting the need for additional courses of MTX or alternative chemotherapy.