Please assess the completion status of the following clinical trial:

Trial Title: Methotrexate and Cytosine in Adult Langerhans Cell Histiocytosis

Study Design Characteristics:
- Allocation: None
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: PHASE2
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~1.DISEASE CHARACTERISTICS:~* Histopathologically confirmed diagnosis of Langerhans cell histiocytosis according to the criteria defined by the Histiocyte Society~* Demonstration of CD1a antigenic determinants on the surface of lesional cells (by immunocytology or immunohistology) or Birbeck granules in lesional cells by electron microscopy~* Considered at risk or low risk according to the following criteria:~  * Multi-system at risk disease, defined as involvement of one or more risk organs (i.e., hematopoietic system, liver, spleen, or lungs)~    1.No single-system lung involvement~ * Multi-system low-risk disease~    1.Multiple organs involved but without involvement of risk organs~ * Single-system disease 1.Multifocal bone disease (i.e., lesions in 2 or more different bones) 2.Localized special site involvement, such as CNS-risk lesions with intracranial soft tissue extension or vertebral lesions with intraspinal soft tissue extension 3.Vault lesions are not regarded as CNS-risk lesions 2.PATIENT CHARACTERISTICS:~    1. Not pregnant or nursing~   2. Negative pregnancy test~   3. Fertile patients must use effective contraception 3.PRIOR CONCURRENT THERAPY:~    <!-- -->~    1. No prior treatment for Langerhans cell histiocytosis~Exclusion Criteria:

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 60 Years
- Healthy Volunteers: f

Study Arms:
- Experimental arm (Type: EXPERIMENTAL): methotrexate,1g/m2,iv.d1 cytosine arabinoside,0.1g/m2,iv.,d1-5

Based on this trial design, predict the completion outcome and termination type (if applicable).