A MULTICENTER RETROSPECTIVE SURVEY OF LANGERHANS CELL HISTIOCYTOSIS -348 CASES OBSERVED BETWEEN 1983 AND 1993

In a retrospective study involving 32 haematology/oncology departments in France, 348 cases of Langerhans' cell histiocytosis diagnosed betw een 1983 and 1993 were collated. The percentage of males was 56.4%. Me dian age at diagnosis was 30.2 months. The median follow up was 35.5 m onths. Initially, 108 patients (31%) had isolated unifocal or bifocal bone involvement, 67 (19%) had isolated multifocal bone involvement, 1 36 (39%) had soft tissue involvement without organ dysfunction, and 37 (11%) had organ dysfunction. Two thirds of the sites of involvement d iagnosed throughout the course of the disease were present at diagnosi s, while the remaining one third appeared during a relapse. Treatment was tailored to the individual patient and was extremely varied, hampe ring any comparison of regimens. Vinblastine with or without steroids was the most common regimen when systemic chemotherapy was used for th e first episode (246/348). Twenty four of the 216 patients received VP 16 as first line treatment. Two patients with progressive multiorgan relapse, despite the use of several drugs, underwent bone marrow trans plantation and are alive and disease free 60 and 22 months later. Alto gether 21.9% of patients had sequelae, including diabetes insipidus in 17.5% of cases. The overall survival rate is 91.7% (confidence interv al 90.7 to 95%) three years after diagnosis. In the univariate analysi s, age less than 1 year, ear, nose, and throat, cutaneous, lymph node, liver, spleen, lung, marrow and intestinal involvement, male sex, pro gressive episodes, the absence of response, and partial responses, wer e associated with a poor vital prognosis. In a multivariate analysis o f prognostic factors, poor early outcome emerged as the most important parameter, closely linked to other poor outcome features such as youn g age and organ dysfunction. It identified a small number of patients with a poor initial response to treatment, for whom intensive treatmen t should be assessed in a phase II trial.