Placental site trophoblastic tumor (PSTT) differs from choriocarcinoma in which key feature that affects treatment choice?
- A PSTT is relatively resistant to methotrexate and EMA-CO; hysterectomy is the primary treatment ✓
- B PSTT produces predominantly hCG while choriocarcinoma produces predominantly human placental lactogen (hPL)
- C PSTT metastasizes to the lungs first while choriocarcinoma metastasizes to the brain first
- D PSTT has a rapid doubling time; choriocarcinoma has a slow doubling time
Correct answer: A. PSTT is relatively resistant to methotrexate and EMA-CO; hysterectomy is the primary treatment
Explanation
PSTT is composed of intermediate trophoblast cells that produce mainly human placental lactogen (hPL) with only minimal hCG, making hCG an unreliable marker. Most importantly, PSTT is relatively chemoresistant — it does not respond reliably to methotrexate or standard EMA-CO regimens (unlike choriocarcinoma). Hysterectomy is the treatment of choice for localized PSTT. Advanced PSTT uses EP/EMA (etoposide-platinum/etoposide-methotrexate-actinomycin) combination. Choriocarcinoma, in contrast, is highly chemoresponsive.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.