Langerhans Cell Histiocytosis: 40 Years' Experience

Objectives: Our study analyzes 40 years' experience with pediatric Langerhans cell histiocytosis patients. Materials and Methods: Between June 1968 and December 2009, 121 patients (79 males, 42 females; median age 4.13 y) were diagnosed at our center (74% monosystemic disease; 26% multi-systemic), treated according to current protocols. We evaluated the response, the survival, and the neuroendocrinological sequelae. Results: Overall survival (OS) for all patients was 93% at 10 years from diagnosis, event-free survival (EFS) 77%. OS for patients younger than 2 years and older than or equal to 2 years was 82% and 97% (P = 0.003); EFS 48% and 87% (P = 0.001). OS for patients diagnosed before and after April 1, 1991 was 84% and 98% (P = 0.007), EFS 66% and 85% (P = 0.03). OS for monosystemic and multisystemic disease was 100% and 71% (P < 0.001); EFS 88% and 45% (P < 0.001). OS for "risk" patients (involvement of bone marrow, spleen, liver, lungs) and "low-risk" patients was 50% and 94% (P = 0.007), EFS 37% and 54% (P = 0.06). Fourteen patients developed diabetes insipidus, 7 patients growth hormone deficiency, 2 hypothyroidism, and 1 neurodegeneration. Conclusions: Our study confirms improvement of pathogenetic knowledge and treatment over the last 20 years. Age at diagnosis older than or equal to 2 years and standardized treatment are associated with improved prognoses. Multisystemic involvement, especially with "risk" organs seem to be correlated to a worse outcome.