A 32-year-old woman treated for complete hydatidiform mole 4 months ago develops a serum β-hCG plateau of 2,400 IU/L over 3 consecutive weekly measurements. Chest CT shows no pulmonary metastases. Pelvic MRI reveals a 2.5 cm uterine lesion. She is assigned FIGO Stage I, WHO risk score 4. Which feature, if additionally present, would reclassify her WHO risk score and mandate combination chemotherapy?
- A Duration of disease >4 months from termination of antecedent pregnancy
- B Serum β-hCG >100,000 IU/L at the time of GTN diagnosis
- C Largest tumor diameter >5 cm on pelvic MRI
- D Prior single-agent chemotherapy failure for this same GTN episode ✓
Explanation
The FIGO/WHO Prognostic Scoring System for GTN assigns points for: antecedent pregnancy type, interval from last pregnancy, pre-treatment β-hCG, largest tumor size, number and site of metastases, and prior chemotherapy. Prior chemotherapy failure (single agent = 2 points, two or more drugs = 4 points) adds significant points and can push a low-risk patient (score <7) into high-risk territory (≥7), mandating EMA-CO combination therapy. Duration of disease (A) scoring: 4–6 months = 1 point, 7–12 months = 2 points — 4 months would be 0 points. Pre-treatment hCG (B): 10,000–100,000 = 2 points, but >100,000 = 4 points — if already scored at 4, total might reach 7 but B alone does not change the requirement. Tumor size (C): >3 cm = 1 point, adds to score. Prior chemotherapy failure (D) definitively reclassifies to high-risk requiring combination therapy.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.