[Treatment of children with multiple system Langerhans cell histiocytosis by Japan Langerhans Cell Histiocytosis Study Group Protocol].

The purpose of this study was to evaluate the efficiency of Japan Langerhans Cell Histiocytosis Study Group (JLSG) Protocol in treatment of children suffering from multiple system langerhans cell histiocytosis (MS-LCH). The clinical features, therapeutic response and prognosis of 11 children who were diagnosed and treated by JLSG in our department during October 2004 through October 2011 were analyzed. Among all 11 cases, 8 males and 3 females, the age at diagnosis was from 3 month to 6.5 years old with a median age of 3 years old. There were 10 cases of LCH with multi-system involvement (MS-LCH) and 1 case of single-system involvement (SS-LCH). Among those MS-LCH patients, 5 patients had risk organ involvement, and the other 5 patients did not develop risk organ involvement. All patients had been treated with JLSG protocol. The results showed that 4 cases achieved good response after 6-week induction treatment and the time of drug discontinuation were 5 - 20 months without relapse; 3 cases achieved partial response after 6-week induction treatment, among them 1 case did not relapse after discontinuation of drugs for 19 months, 1 case was still receiving maintenance treatment, 1 case abandoned induction treatment; 4 patients got no response (NR) or progressive disease after 6-week of induction treatment and were switched to salvage therapy, among them, 2 patients had stopped treatment for 2 - 20 months without relapse, 1 patient was still receiving maintenance treatment, one had changed to another therapy. It is concluded that the most of childhood LCH can be effectively controlled by immunochemical therapy based on the JLSG protocol. For children with LCH who has a poor response after 6-week induction treatment, LCH can still be well controlled if switched to salvage treatment.