# Stage I placental site trophoblastic tumor with complete response after pembrolizumab

## TL;DR

A patient with a rare placental tumor achieved full recovery using pembrolizumab, a drug that helps the immune system fight cancer.

## Contribution

This case shows that PD-1 inhibitors can be effective for PSTT while preserving fertility.

## Key findings

- Pembrolizumab led to a complete and sustained response in a PSTT patient.
- PD-L1 expression in PSTT suggests potential for PD-1/PD-L1 inhibitors as treatment.
- PD-1 inhibition may be beneficial when fertility-sparing options are limited.

## Abstract

•Placental site trophoblastic tumors (PSTT) express PD-L1, making them ideal targets for PD-1 and PD-L1 inhibitors.•For this PSTT patient seeking fertility-sparing treatment, PD-1 inhibition demonstrated complete and sustained response.•Despite anti PD-1 toxicity, there is potential for significant benefit when no alternative fertility-sparing options exists.

Placental site trophoblastic tumors (PSTT) express PD-L1, making them ideal targets for PD-1 and PD-L1 inhibitors.

For this PSTT patient seeking fertility-sparing treatment, PD-1 inhibition demonstrated complete and sustained response.

Despite anti PD-1 toxicity, there is potential for significant benefit when no alternative fertility-sparing options exists.