Prognostic factors and clinical outcomes in pediatric Langerhans Cell Histiocytosis: a retrospective cohort study on event-free survival.

Abstract

Objectives: Langerhans Cell Histiocytosis (LCH) is an inflammatory myeloid neoplasm with heterogeneous outcomes. This study aimed to identify independent risk factors influencing event-free survival (EFS) in pediatric LCH, focusing on initial white blood cell (WBC) counts and disease extent.

Methods: We retrospectively analyzed 67 pediatric LCH patients with bone involvement treated at Hebei Children's Hospital, Hebei Clinical Medicine Research Center for Children's Health and Diseases between 2013 and 2022. The primary endpoint was EFS. Cox proportional hazards regression models determined predictors of adverse outcomes.

Results: The 3-year EFS rate was 76.1% (median follow-up: 48 months). Univariate analysis linked multiple disease sites, risk-organ involvement, CNS risk site involvement, diabetes insipidus, and elevated WBC count to poor EFS. In multivariate analysis, only multiple site involvement (Hazard Ratio [HR] = 3.12, p = 0.025) and an elevated initial WBC count (>10 × 10⁹/L) (HR = 2.89, p = 0.034) remained independent predictors.

Discussion: While risk-organ involvement is a traditional stratifier, systemic inflammatory burden, reflected by leukocytosis, offers independent prognostic value. Patients with elevated WBC counts or multisite disease warrant intensive monitoring.

Conclusion: Elevated initial WBC count and multiple site involvement independently predict shorter EFS in pediatric LCH. Integrating these markers into risk stratification could optimize therapies.