To assess the value of chemotherapy and radiotherapy in children with malignant peripheral nerve sheath tumors (MPNSTs) and to identify risk factors associated with outcome.

A total of 167 untreated eligible patients enrolled onto the Italian and German studies between 1975 and 1998 entered this analysis. Seventeen percent of patients had neurofibromatosis type 1 (NF1). Chemotherapy was administered to 74% of patients; radiotherapy was administered to 38% of patients.

With a median follow-up of 7 years, 5-year overall survival (OS) and progression-free survival (PFS) were 51% and 37%, respectively. The 5-year OS and PFS by Intergroup Rhabdomyosarcoma Study (IRS) groupings were as follows: group I, 82% and 61%; group II, 62% and 37%; group III, 32% and 27%; group IV, 26% and 21%, respectively. Univariate analysis identified IRS groups, size, invasiveness, primary site, age, and presence of NF1 as prognostic factors; multivariate analysis identified absence of NF1, tumor invasiveness T1, IRS groups I to II and extremity of primary site as independent favorable factors for OS. A trend was observed toward a benefit from radiotherapy after initial gross resection. The overall response rate to primary chemotherapy, including minor responses, in group III patients was 45%.

MPNST is an aggressive tumor for which complete surgical resection is the mainstay of successful treatment. Postoperative radiotherapy may have a role in improving local control in patients with minimal residual tumor. The reported responses to primary chemotherapy suggest that it may be effective in patients with tumor considered unresectable at diagnosis.