The outcome of patients with low risk gestational trophoblastic neoplasia treated with single agent intramuscular methotrexate and oral folinic acid.

BACKGROUND

Gestational trophoblastic neoplasia (GTN) persisting despite local treatment requires chemotherapy. In 2000, the revised International Federation of Gynaecology and Obstetrics (FIGO)/World Health Organisation (WHO) staging system was introduced, classifying patients as at 'low' or 'high' risk for resistance to single agent treatment.

PATIENTS AND METHODS

We have evaluated the complete response rates of patients with low risk GTN treated with 2 weekly intramuscular (IM) methotrexate 50mg four doses days 1, 3, 5, 7 and oral folinic acid 15 mg days 2, 4, 6, 8 (MTX/FA). Patient data between January 2000 and December 2011 were collated and the relationships between FIGO/WHO risk score and outcomes evaluated.

RESULTS

Two hundred and eighty nine patients were treated with single agent IM MTX/FA and assessed for treatment response. 29/36 (81%) patients with a FIGO/WHO total score of 6 developed resistance to MTX/FA compared with 87/253 (34%) patients with a score of 0-5 (p ≤ 0.0001). Significantly higher rates of resistance were found for patients with an hCG level of >100,000 iu/l compared to an hCG level of <100,000 iu/l (84% versus 34% p ≤ 0.0001). All patients were eventually cured with chemotherapy or surgical salvage.

CONCLUSIONS

Patients with low risk GTN that have a FIGO/WHO score of 6 or hCG level of >100,000 iu/l have high rates of resistance to MTX/FA and require further treatment. Revision of the FIGO/WHO scoring system may be appropriate to enable selection of more effective first line chemotherapy.