Hungarian experience with Langerhans cell histiocytosis in childhood.

The Langerhans cell histiocytosis (LCH) in children is relatively rare and the long-term analysis of therapy results has not been done yet in Hungary. The aim of this study was to investigate the incidence, clinical features, prognostic risk factors, and treatment results of children's LCH in Hungary in a 20-year period. Children less than 18 years of age with newly diagnosed LCH in Hungary were entered in this study. Clinical data of all children with LCH were reported to the National Childhood Cancer Registry in Hungary from 1981 to 2000. The clinical files were collected and abstracted for information regarding age at diagnosis, gender, disease characteristics, treatment, and outcome of treatment. Median follow-up duration of surviving patients is 10.98 years. Between January 1981 and December 2000, 111 children under 18 years of age were newly diagnosed with LCH in Hungary. The annual incidence of LCH in children younger than 18 years of age was 2.24/million children. The male-female ratio was 1.36:1; the mean age was 4 years 11 months. Thirty-eight children had localized disease and in 73 cases systemic dissemination was found already at the time of diagnosis. Twenty-two patients were treated only by local surgery, 7 by surgery with local irradiation, and 5 children got only local irradiation. In 2 cases remission was achieved with local steroid administration. Seventy-five patients received chemotherapy. In the 20 years of the study 14 children died, 9 due to the progression of the disease. Sixteen patients had relapse with a mean of 2.16 +/- 1.29 years after the first diagnosis. Three patients with relapse got chemotherapy generally used in lymphoma and remission was achieved. The overall survival of all patients (n = 111) was 88.3 +/- 3.1% at 5 years and 87.3 +/- 3.2% at 10 and 20 years. Childhood LCH is a well-treatable disease and the survival rate is high. Even disseminated diseases have a quite good prognosis in childhood.