TREATMENT OF LOW-RISK METASTATIC GESTATIONAL TROPHOBLASTIC TUMORS WITH SINGLE-AGENT CHEMOTHERAPY

OBJECTIVE: Our purpose was to evaluate the efficacy and toxicity of si ngle-agent chemotherapy and to identify risk factors associated with c hemotherapy resistance in the treatment of low-risk metastatic gestati onal trophoblastic tumors. STUDY DESIGN: We reviewed the records of al l patients with gestational trophoblastic tumors treated with single-a gent chemotherapy at the John I. Brewer Trophoblastic Disease Center o f Northwestern University between 1962 and 1992. A total of 92 patient s with low-risk metastatic gestational trophoblastic tumors by Nationa l Cancer Institute criteria were identified. Patients received methotr exate (n = 61), actinomycin D (n = 4), alternating methotrexate and ac tinomycin D (n = 5), or hysterectomy with methotrexate (n = 20) or act inomycin D (n = 2). RESULTS: All 92 patients with low-risk metastatic gestational trophoblastic tumors were cured. Primary remission was ach ieved with initial single-agent therapy in 62 patients (67.4%). A seco nd sequential single agent was used because of drug resistance in 20 p atients (21.7%) or drug toxicity in 10 patients (10.9%). Only one pati ent (1%) needed multiagent chemotherapy to be cured. Adjuvant hysterec tomy was performed in 22 patients (23.9%). Surgery was not required to remove resistant tumor foci. Chemotherapy toxicity, most commonly sto matitis, occurred in 36 patients (39.1%), but none of these effects wa s 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.