De-escalation strategies and fertility preservation in Stage I placental site trophoblastic tumor: an individual patient data systematic review and institutional series.

This individual patient data review and institutional series asked whether the ISAP (interval since antecedent pregnancy) cutoff recommended in 2025 guidelines is statistically sound, whether pathological factors still matter, and which Stage I placental site trophoblastic tumor (PSTT) patients could safely avoid chemotherapy or undergo fertility-sparing surgery. Across 229 patients, an ISAP of 48 months or more was the optimal cutoff and independently predicted both progression-free and overall survival, while pathological risk factors were not prognostic. Low-risk patients treated with surgery alone had no progression or deaths, and fertility-sparing surgery with salvage hysterectomy when needed yielded good survival and documented subsequent pregnancies, though prospective trials are still needed to confirm chemotherapy can be omitted.