Predicting factors associated with resistance to initial Methotrexate
treatment in women with low-risk gestational trophoblastic neoplasia: a
retrospective study
Abstract
Objectives To compare clinical characteristics and factors predictive of
resistance to initial treatment with Methotrexate-folinic acid (MTX-FA)
in women with low-risk gestational trophoblastic neoplasia (GTN). Design
A retrospective study Setting A tertiary center Populations Patients
diagnosed with low-risk GTN. Methods: Demographic data, disease
characteristics, treatment response, toxicity and data of the subsequent
pregnancy were collected and analyzed. Main outcome measures Groups of
patients who were responsive or resistance to treatment were compared.
Stepwise logistic regression analysis was used to identify factors
predictive of resistance to Methotrexate chemotherapy. Results Totally,
113 patients were eligible for analysis. The primary remission rate was
55.8% with first-line MTX-FA. All others patients achieved remission by
subsequent treatment with Actinomycin D or multiple-agents chemotherapy.
Relapse of disease was found in 4.4% and the overall survival rate was
99.1%. Univariate analysis showed that pre-treatment serum hCG,
neutrophil-to-lymphocyte ratio at baseline, and serum hCG ratio of the
first three consecutive cycles (C) were significantly associated with
resistance to MTX-FA. Independent factors that predict failure to
respond to first-line MTX-FA were pre-treatment serum hCG ≥15,000 IU/L
(OR 3.95; 95%CI = 1.48-10.52; p=0.006), a less than 4.8-fold reduction
of serum hCG between cycle 1 and cycle 2 (C1/C2) (OR 4.08; 95%CI =
1.60-10.39; p=0.003), and a less than 7-fold reduction of serum hCG from
cycle 2 to cycle 3 (C2/C3) (OR 10.15; 95%CI = 3.10-33.30;
p<0.001). Conclusions First-line MTX-FA treatment is effective
in 55.8% of patients. Pre-treatment serum hCG, and hCG ratio between
consecutive treatment cycles predicts initial treatment failure.