The WHO score predicts treatment outcome in low risk gestational trophoblastic neoplasia patients treated with weekly intramuscular methotrexate

Background: Gestational trophoblastic neoplasia (GTN) includes a spectrum of disease ranging from hydatidifrom mole to choriocarcinoma. Low risk GTN is defined as persistent molar pregnancy with a WHO score lower than seven. The optimal chemotherapeutic regimen still remains controversial. Aim: The objectives of this study was to determine efficacy and safety of weekly intramuscular methotrexte in the treatment of low risk gestational trophoblastic neoplasia.(LRGTN) and also identify prognostic factors associated with treatment failure, necessitating second line chemotherapy. Materials and Methods: Sixty-six women with LRGTN from 2001 to 2009 were treated with weekly intramuscular methotrexate at 40mg/m(2) as first line therapy. Monitoring of treatment was done with weekly checking of beta hCG level. Three consecutive negative beta hCG measurements showed complete response. After first negative beta hCG measurement, one additional dose was administered for consolidation. Results: Of 66 patients, who started the treatment five continued their treatment in other medical centres and were excluded from final analysis for treatment evaluation, and seven discontinued first line therapy because of hepatotoxicity. Of the remaining 54, complete remission occurred in 43 (79.6%) and eleven were resistant to first line therapy. Mean WHO score prior to starting chemotherapy was significantly different between two groups of response and resistance according to our data. Change of treatment to second line Actinomycin-D was necessary in eigtheen cases because of resistance to first line in eleven and liver enzyme elevation in seven patients. Sixteen of these 18 responded to Actinomycin-D as second line and one needed hysterectomy for complete response. One patient received multiagent chemotherapy for complete remission. Conclusion: We recommend this effective and safe method of chemotherapy for women with LRGTN. According to our data, lower mean WHO score predicts a better outcome for this regimen.