Response to initial treatment of multisystem langerhans cell histiocytosis: An important prognostic indicator

Abstract

Background Reliable prediction of prognosis allowing risk‐adapted therapy remains a major issue in the management of multisystem Langerhans cell histiocytosis (LCH). In a recent publication of the International LCH Study Group, response to initial therapy appears to be a reliable outcome predictor. The aim of this study is to test this observation in a cohort of patients treated with more intensive initial therapy. Furthermore, we compare the predictive value of response to initial therapy to some other well‐established stratification systems. Procedure Response to initial combination chemotherapy (prednisolone, vinblastine, and etoposide) at 6 weeks and its prognostic value was evaluated retrospectively in 63 patients with multisystem LCH from the DAL‐HX 83 and 90 Studies, and correlated to some established scoring systems from the literature. Results After 6 weeks of therapy, 50/63 (79%) patients qualified as responders, 4/63 (7%) patients showed intermediate response, and 9/63 (14%) patients did not respond. Probability of survival at 5 years was 0.94 ± 0.03 for responders, 0.75 ± 0.22 for patients with intermediate response, and only 0.11 ± 0.10 for non‐responders. Conclusions Response to initial therapy appears to be a reliable prognostic predictor. Compared to the published international LCH‐I Study, our results suggest that more intensive initial treatment allows a better discrimination between responders and non‐responders. This allows to identify a subgroup of patients with extremely poor prognosis (mortality rate 90%) relatively early in the disease course. Med Pediatr Oncol 2002;39:581–585.