Relapse rates after two versus three consolidation courses of methotrexate in the treatment of low-risk gestational trophoblastic neoplasia.

OBJECTIVE: Methotrexate (MTX) alternating with folinic acid is a commonly used treatment regimen for low-risk gestational trophoblastic neoplasia (GTN). In The Netherlands, two courses of MTX are administered after normalization of serum human chorionic gonadotrophin (hCG) levels (consolidation courses), whereas in the United Kingdom, three consolidation courses are given. In a retrospective setting we compared relapse rates of women completing MTX therapy for low-risk GTN in The Netherlands and the UK.
METHODS: From 1980 to 2008, 351 patients were collected from the Dutch Central Registry for Hydatidiform Moles and records from the Dutch Working Party on Trophoblastic Disease. From the Charing Cross Hospital Trophoblast Disease Centre (London), 600 low-risk GTN patients were identified from 1992 to 2008.
RESULTS: In 4.0% of patients relapse occurred after MTX treatment with three consolidation courses, whereas 8.3% of patients relapsed after MTX treatment with two consolidation courses (p=0.006). Although patients from The Netherlands had a higher level of hCG (p<0.001) and more patients had metastases before the start of treatment (p=0.012), the number of courses of MTX to achieve a normal hCG did not differ significantly between patients from The Netherlands and the UK (p=0.375).
CONCLUSIONS: Relapse rates were higher in patients treated with two consolidation courses of MTX. Although other factors might have influenced the observed difference in relapse rates, three courses of consolidation chemotherapy may be preferable to two in the treatment of low-risk GTN in order to decrease the risk of disease relapse. A prospective randomized study would be required to confirm these findings.