Outcome analysis of patients with transformed teratoma to primitive neuroectodermal tumor

The emergence of a primitive neuroectodermal tumor (PNET) within a germ-cell tumor (GCT) is rare. We assess the prognosis and response to treatment. Eighty-one patients were identified. Selected patients were treated with cyclophosphamide 1200 mg/m2, doxorubicin 75 mg/m2, and vincristine 2 mg i.v. alternating with ifosfamide 1.8 g/m2 × 5 days plus etoposide 100 mg/m2 × 5 days (CAV/IE). Ewing's sarcoma (EWS) translocation was assessed using a FISH-based method. Median follow-up was 41 months. Seventy-six patients had PNET in the primary tumor or in initial metastasis. Five harbored PNET only at relapse. Twenty-six of 76 underwent primary retroperitoneal lymph node dissection, 13 of whom had retroperitoneal PNET and four are dead of disease (DOD). Fifty of 76 were initially treated with GCT chemotherapy (n = 49) or CAV/IE (n = 1). Twenty-seven of these 50 underwent complete postchemotherapy resection of residual PNET and 17 are DOD. Ten patients received CAV/IE. Eight achieved an objective response, and five are currently alive. One of the 14 specimens examined carried the EWS translocation. PNET of GCT origin is associated with an adverse outcome. For low-volume disease, surgery is the optimal initial therapy. CAV/IE may have a role in patients with unresectable disease.