Chronic health conditions after childhood Langerhans cell histiocytosis: Results from the Swiss Childhood Cancer Survivor Study.

PURPOSE Langerhans cell histiocytosis (LCH) is a rare disease characterized by dysregulated proliferation of myeloid marrow progenitors and subsequent organ infiltration. While LCH is associated with a favorable prognosis, some survivors may develop chronic health conditions (CHC) because of the disease. In this study, we aimed to assess the spectrum and prevalence of CHC among LCH survivors compared with siblings and identify factors associated with the development of CHC. METHODS The Swiss Childhood Cancer Survivor Study sent questionnaires to all ≥ 5-year LCH survivors registered in the Swiss Childhood Cancer Registry and diagnosed between 1976 and 2015. Siblings also received similar questionnaires. We compared CHC prevalence between LCH survivors and siblings and used logistic regression to identify determinants of CHC. RESULTS A total of 123 LCH survivors participated in the study, with a response rate of 69%. Median time since diagnosis was 13 years (interquartile range 9-20). Among LCH survivors, 59% had at least one CHC. Cardiovascular (13% vs. 6%), endocrine (15% vs. 2%), musculoskeletal (22% vs. 13%), and digestive (15% vs. 8%) CHC were more common among LCH survivors compared to siblings (all p < 0.05). Factors most strongly associated with the occurrence of CHC were multisystem LCH, multifocal bone involvement, and involvement of the pituitary gland. CONCLUSIONS More than half of long-term LCH survivors suffered from one or more CHC and were affected considerably more than siblings. IMPLICATIONS FOR CANCER SURVIVORS LCH survivors in follow-up care should be screened especially for cardiovascular, endocrine, musculoskeletal, and digestive conditions.