Therapeutic Outcomes of Langerhans' Cell Histiocytosis / 대한혈액학회지

ABSTRACT

BACKGROUND: Langerhans' cell histiocytosis is a proliferative histiocytic disorder of unknown cause formerly referred to histiocytosis X, with pathologic characteristics of abnormal proliferation of histiocytes which belong to the mononuclear phagocytes. The clinical manifestations range in severity from solitary lytic bone lesions to fatal multisystem disease, typically with indolent clinical courses. The authors reported here, the clinical features and therapeutic outcomes of Langerhans' cell histiocytosis according to stage and prognostic features. METHODS: We reviewed the medical records of 38 cases with Langerhans' cell histiocytosis confirmed by biopsy from March 1983 to March 1998 in Severance hospital for disease course, treatment, and late sequelae. RESULTS: 1) Median age of the patients was 3 years-old, and the male to female ratio was 2.2:1. 2) Fifteen cases were less than 2 years of age, 21 had soft tissue involvements, 10 had more than 4 organ involvement, and 8 had involved organ dysfunction. 3) As for the clinical stages, 19 cases were in stage I, 9 in stage II, 4 in stage III, and 6 in stage IV. As for the pathologic stages, 15 had monostic disease, 2 had polyostic disease, and 21 had multisytemic disease. 4) The incidence of more than 4 organ involvement in cases or = 2 years [53.3% (8/15) vs 8.7% (2/23), P=0.004], and the incidence of organ dysfunction in cases or = 2 years [33.3% (5/15) vs 3% (3/23)], indicating that cases or = 15 years. There was a significant correlation between the presence of more than 4 organ involvement and organ dysfunction (P=0.041). 5) The response rate of all cases was 71% (27 cases), and the response rate of 25 cases who received chemotherapy was 60% (15 cases). There was no difference in the response rate according to the type of chemotherapy. Overall survival rate was 63.4% at 50 months, disease-free survival rate was 56.7% at 24 months. The disease free survival rate was significantly lower in cases younger than 2 years of age than cases older than 2 years of age (P=0.047), in cases with 4 or more organs involvement than 3 or less (P=0.0002), in cases with evidence of organ dysfunction than without evidence of organ dysfunction (P=0.082), and in cases with soft tissue involvement than with only bone involvement (P=0.043). There was significant differences in disease free survival rate according to clinical stage (P=0.001). The overall survival and disease free survival rate of the cases older than 15 years of age were similar to those of the cases younger than 15 years of age were similar to those of the cases younger than 15 years of age. 6) Five cases died during follow-up periods, organ involvement, and organ dysfunction were found to be important prognostic factors, and cases with lesions limited to skeletal system showed more than 90% of survival rate. In the future, clinical investigation enrolled with more cases about the difference of clinical features and therapeutic outcomes between adult patients and pediatric patients should be warranted.