Effects of primary chemotherapy with single methotrexate on low-risk gestational trophoblastic neoplasia and influencing factors thereof

Abstract

To evaluate the effects of primary chemotherapy with single-agent methotrexate (MTX) on low-risk gestational trophoblastic neoplasia (GTN) and the influencing factors thereof. Sixty-one GTN patients with the score of < or = 6 according to the new International Federation of Gynecology and Obstetrics (FIGO) scoring system (2000) were divided into 2 groups: 51 patients were treated with single MTX 0.4 mg/kg daily for 5 days (MTX 5 d group), and 10 patients were treated with MTX on the days 1, 3, 5, and 7, and with folinic acid (FA) 0.1 mg/kg on the days 2, 4, 6, and 8 (MTX + FA group), both group with an interval of treatment course of 2 weeks. The serum level of human chorionic gonadotropin (hCG) was detected every week. If a plateau or increase of serum hCG appeared between 2 examination results, meaning tolerance to MTX, the patients concerned had to undergo different regimens of salvage chemotherapy, all with MTX as one of their components. Univariate and multivariate methods were used to analyze the relationships of different factors to the outcomes of chemotherapy. Thirty-five of the 51 patients of the MTX 5d group (68.6%) achieved complete primary remission, 3 of the 10 patients of the MTX + FA group achieved complete primary remission, and all patients achieved complete remission after salvage chemotherapy. Univariate analysis showed that the mean pretreatment serum level of hCG, duration between antecedent pregnancy and start of treatment, size of tumor, FIGO score, specific regimen of MTX were significantly associated with outcome of chemotherapy (P = 0.004, 0.022, 0.017, 0.005, 0.021 respectively). Logistic regression analysis showed that only three independent factors predictive for the outcome of chemotherapy: MTX regimen (OR = 2.476), FIGO score (OR = 1.431), and pretreatment hCG titer (OR = 1.001). Primary chemotherapy with single MTX regimen may still be one of the options for patients with low-risk GTN according to the new FIGO scoring system, though the rate of complete primary remission appears to be lower. All patients with low-risk GTN achieve complete remission after salvage chemotherapy. MTX regimen, FIGO score, and pretreatment hCG are independent risk factors of outcome of single MTX chemotherapy.