Neoadjuvant chemotherapy for peripheral malignant neuroectodermal tumor ofbone: Recent experience at the Istituto Rizzoli

Purpose: The results achieved in 44 patients with nonmetastatic peripheral neuroectodermal tumor (PNET) of bone treated with neoadjuvant chemotherapy are reported. patients and Methods: A six-drug regimen of chemotherapy (vincristine, doxo rubicin, dactinomycin, cyclophosphamide, ifosfomide, and etoposide) was adm inistered to all patients. Local treatment consisted of surgery in 20 patie nts, surgery followed by radiotherapy in 13, and radiotherapy only in 11. Results: At a mean follow-up of 4.5 years (range, 2 to 7 years), 23 patient s (52%) remain event-free, 20 have relapsed (45%), and one has died of chem otherapy-related toxicity. The 5-year event-free survival and overall survi val were 54.2% and 62.7%, respectively. Ta assess the prognostic significan ce of neural differentiation in the family of Ewing's sarcoma, these result s have been compared with the outcomes of 138 concomitant patients with typ ical Ewing's sarcoma (TES) who were treated according to the same protocol. Of these, 103 (75%) remained continuously event-free, 34 (24%) relapsed, a nd one died of chemothempy-related toxicity. It follows that PNET patients treated with this chemotherapy regimen have a significantly worse prognosis than typical ES patients (5-year event-free survival, 54.2% v 70.6%, P < . 012; 5-year overall survival, 62.7% v 78.3%, P < .002). Conclusion: The authors conclude that studies into new adjuvant therapy for Ewing's sarcoma modulated according to risk of relapse should also conside r neural differentiation as a risk factor. (C) 2000 by American Society of Clinical Oncology.