Exploration of treatment in childhood Langerhans cell histiocytosis based on inflammatory and tumorous symptoms: A Pilot study

Abstract Background: The outcome of multisystem childhood Langerhans cell histiocytosis (LCH), especially risk organ (RO) involvement patients, treated by the international traditional schemes had not been satisfactory and had a high incidence of reactivation with late sequelae. We observed that patients with different clinical symptoms showed different therapeutic responses to different drugs, suggesting that the method of grouping and selecting treatment strategies based only on the number of organs involved is inadequate. Based on the definition of LCH as an inflammatory myeloid tumor, this study innovatively divided children with LCH into inflammatory symptoms’ group and tumor symptoms’ group, and given different intensity treatment regimens accordingly, to explore a more appropriate treatment strategy. \Methods: According to the clinical manifestations, 37 cases of children were divided into Group A (inflammatory symptoms) and Group B (tumor symptoms). Initial treatment, Group A used vindesine (VDS) and methylprednisolone (PSL); Group B used VDS, PSL, pirarubicin(THP) and cyclophosphamide (CTX). Treatment response was evaluated 6 weeks after the start of induction therapy in all patients, which assessed according to two criterias consisting of disease status and clinical scores of symptoms. Results: Clinical scores pre- and post-treatment were 1.22 ± 0.547 and 0.00 ± 0.00 in Group A compared with 14.79 ± 1.686 and 1.00 ± 1.563 in Group B. Patients in both groups were all able to successfully enter maintenance treatment without progressive disease state. The overall survival (OS) of 4-year follow-up was 100% in both groups. The 4-year event-free survival (EFS) was 94.4% in Group A and 89.5% in Group B, respectively. There were no obvious adverse events in Group A, and the main adverse events in Group B were alopecia and non-lethal hematological toxicity. Conclusion: Stratification according to patients’ clinical symptoms, with low-intensity treatment for inflammatory symptoms (mild manifestations) and intensive treatment with multiple drugs for tumor symptoms (severe manifestations), is a positive exploration that simplifies stratification method, achieves good long-term remission of the disease, and obtains a higher survival rate and quality of life, which seemed to be more appropriate for LCH patients.