The 16-year experience in treating low-risk gestational trophoblastic neoplasia patients with failed primary methotrexate chemotherapy

OBJECTIVE: To assess the outcomes and toxic effects of 5-day actinomycin D (Act-D) salvage therapy and to explore the predictors of Act-D resistance in patients with low-risk gestational trophoblastic neoplasia (GTN)who failed 5-day methotrexate (MTX) chemotherapy. METHODS: This retrospective study analyzed patients with low-risk GTN administered Act-D salvage therapy after failing MTX chemotherapy at Women's Hospital, School of Medicine Zhejiang University between January 2000 and December 2015. The clinical parameters of these patients were collected and analyzed. RESULTS: The final analysis included 89 cases. Of these, 73 cases (82.02%) responded to salvage Act-D. The remaining 16 resistant cases were switched to etoposide, MTX, Act-D/cyclophosphamide, and vincristine chemotherapy and achieved complete remission. Serum human chorionic gonadotrophin levels before Act-D salvage therapy (hCG(Act-D))in the Act-D-resistant cases were significantly higher than those in the Act-D responders (median 605 vs. 103 IU/L, p=0.009). However, the range of hCG(Act-D) values in Act-D responders was wider than that in Act-D-resistant cases (5.76–16,664 IU/L vs. 11.43–6,732 IU/L). Thus, assigning a general cut-off value was difficult considering the individual setting. Except for 2 cases requiring other salvage regimens due to Act-D toxicity, 97.80% of cases (89/91) tolerated the toxicity. During at least 1-year follow-up, the survival rate was 100.00% and no case developed recurrence. CONCLUSION: Based on the good therapeutic effect and tolerable toxicity, we recommend Act-D salvage therapy for all patients with low-risk GTN who fail primary MTX chemotherapy. The higher serum hCG levels before Act-D salvage therapy may be associated with resistance to this treatment.