The objective of this study was to determine the efficacy of weekly intramuscular (IM) methotrexate without dose escalation as first-line chemotherapy for low-risk gestational trophoblastic neoplasia (LRGTN).Thirty-three women with post-molar LRGTN in the division of gynecology oncology at the Shiraz University of Medical Sciences were treated with weekly IM methotrexate at 30 mg/m(2) without dose escalation. The serum level of beta-hCG was detected every week. After the first negative beta-hCG level, one more cycle was administered as consolidation. Complete response (CR) was defined as the attainment of serum beta-hCG level of 5 IU/L or less measured on three consecutive weeks.Twenty-one of 33 women (63.6%) achieved CR with weekly IM injection of 30 mg/m(2) methotrexate. Ten of 12 patients with weekly IM methotrexate failure had a CR after one to three courses of dactinomycin administered at 1.25 mg/m(2) intravenously every 2 weeks. Two patients needed multiple-agent chemotherapy for remission.Weekly methotrexate without dose escalation may be an appropriate option for primary chemotherapy of patients with LRGTN.
