Treatment of low-risk metastatic gestational trophoblastic tumors with single-agent chemotherapy.

OBJECTIVE: Our purpose was to evaluate the efficacy and toxicity of single-agent chemotherapy and to identify risk factors associated with chemotherapy resistance in the treatment of low-risk metastatic gestational trophoblastic tumors.

STUDY DESIGN: We reviewed the records of all patients with gestational trophoblastic tumors treated with single-agent chemotherapy at the John I. Brewer Trophoblastic Disease Center of Northwestern University between 1962 and 1992. A total of 92 patients with low-risk metastatic gestational trophoblastic tumors by National Cancer Institute criteria were identified. Patients received methotrexate (n = 61), actinomycin D (n = 4), alternating methotrexate and actinomycin D (n = 5), or hysterectomy with methotrexate (n = 20) or actinomycin D (n = 2).

RESULTS: All 92 patients with low-risk metastatic gestational trophoblastic tumors were cured. Primary remission was achieved with initial single-agent therapy in 62 patients (67.4%). A second sequential single agent was used because of drug resistance in 20 patients (21.7%) or drug toxicity in 10 patients (10.9%). Only one patient (1%) needed multiagent chemotherapy to be cured. Adjuvant hysterectomy was performed in 22 patients (23.9%). Surgery was not required to remove resistant tumor foci. Chemotherapy toxicity, most commonly stomatitis, occurred in 36 patients (39.1%), but none of these effects was life threatening. Large vaginal metastasis was the only identifiable factor significantly associated with failure of initial single-agent chemotherapy (p = 0.03).

CONCLUSION: In this large series of patients with low-risk metastatic gestational trophoblastic tumors, sequential single-agent chemotherapy with methotrexate and actinomycin D provided safe and extremely effective treatment.