A 33-year-old woman is diagnosed with low-risk gestational trophoblastic neoplasia (FIGO score 3) following a complete hydatidiform mole. She is started on weekly intramuscular methotrexate (30 mg/m²). After 3 cycles, her β-hCG plateaus at 45 IU/L (was 42, then 44, then 45 IU/L). What is the most appropriate next step?
- A Switch to single-agent actinomycin-D ✓
- B Continue methotrexate for 3 more cycles
- C Switch to EMA-CO multi-agent chemotherapy
- D Perform hysterectomy
Correct answer: A. Switch to single-agent actinomycin-D
Explanation
Plateau of β-hCG during single-agent chemotherapy indicates drug resistance. The standard approach is to switch to the alternative single-agent regimen (actinomycin-D) before escalating to multi-agent therapy. EMA-CO is reserved for high-risk disease or failure of both single-agent regimens. Continuing the same agent is ineffective once resistance is demonstrated. Hysterectomy is not first-line for low-risk GTN and is reserved for cases with significant uterine bleeding or localized disease refractory to chemotherapy.
Reference: NCCN Guidelines: Gestational Trophoblastic Neoplasia, Version 1.2024 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.