# Clinical characteristics, genomic profiling, treatments, and outcomes of Langerhans cell sarcoma

## TL;DR

This study analyzes 13 cases of Langerhans cell sarcoma, a rare cancer, to understand its clinical features, genetic mutations, and treatment outcomes.

## Contribution

The study provides new clinical and genomic insights into LCS through a rare patient cohort and evaluates the efficacy of targeted therapies.

## Key findings

- CBL mutations were detected in 33.3% of LCS patients.
- Targeted therapies showed promising efficacy in relapsed or refractory LCS cases.
- The 2-year progression-free survival rate was 32.9%, indicating poor PFS in LCS patients.

## Abstract

Langerhans cell sarcoma (LCS), an exceptionally rare and aggressive neoplasm, remains poorly characterized due to its scarcity. To address this knowledge gap, we conducted a retrospective analysis of 13 LCS patients. This retrospective study included patients ≥ 18 years old with biopsy proven LCS from October 2015 to April 2025.

The median age at diagnosis was 59 years (range: 33–71). The most commonly affected organs were the subcutaneous soft tissue (61.5%), followed by lymph nodes (53.8%), skin (30.8%), and bone (23.1%). CBL was the most common mutation, detected in four patients (33.3%). Notably, first-line treatment options included surgery and chemotherapy, with an overall response rate of 53.8%. Among all the relapsed or refractory patients, three eventually received targeted therapies (two trametinib and one niraparib), demonstrating promising efficacy with all patients achieved partial remission. With a median follow-up of 18.2 months (range: 2.6–93.1), the estimated 2-year overall survival rate was 92.3%, while the estimated 2-year progression-free survival (PFS) rate stood at 32.9%.

In our cohort of LCS, we found that the PFS of LCS was poor. Genetic sequencing and the use of targeted therapies may offer a survival advantage for patients with LCS.

Not applicable.

The online version contains supplementary material available at 10.1186/s13023-026-04199-4.