A Children's Oncology Group trial investigated the addition of cyclophosphamide to standard-dose PEB. The addition of cyclophosphamide was feasible and well tolerated at all dose levels, but there was no evidence that adding cyclophosphamide improves efficacy.
Malignant Extragonadal Extracranial GCTs (Sacrococcygeal Sites)
Sacrococcygeal GCTs are common extragonadal tumors that occur in very young children, predominantly young females. The tumors are usually diagnosed at birth, when large external lesions predominate (usually mature or immature teratomas), or later in the first years of life, when presacral lesions with higher malignancy rates predominate.
Malignant sacrococcygeal tumors are usually very advanced at diagnosis; two-thirds of patients have locoregional disease, and metastases are present in 50% of patients.[7,12,13] Because of their advanced stage at presentation, the management of sacrococcygeal tumors requires a multimodal approach with platinum-based chemotherapy followed by delayed tumor resection.
Platinum-based therapies, with either cisplatin or carboplatin, are the cornerstone of treatment. The PEB regimen or the JEB regimen produces event-free survival (EFS) rates of 75% to 85% and OS rates of 80% to 90%.[7,8] Surgery may be facilitated by preoperative chemotherapy. In any patient with a sacrococcygeal GCT, resection of the coccyx is mandatory.[7,8]
Completeness of surgical resection is an important prognostic factor, as shown in the following circumstances:[7,8]
- Resected tumors with negative microscopic margins-EFS rates of greater than 90%.
- Resected tumors with microscopic margins-EFS rates of 75% to 85%.
- Resected tumors with macroscopic residual disease-EFS rates of less than 40%.
Malignant Extragonadal Extracranial GCTs (Mediastinal)
Mediastinal GCTs account for 15% to 20% of malignant extragonadal extracranial GCTs in children. The histology of mediastinal GCT is dependent on age, with teratomas predominating among infants and yolk sac tumor histology predominating among children aged 1 to 4 years.
Children with mediastinal teratomas are treated with tumor resection, which is curative in almost all patients. Children with malignant, nonmetastatic mediastinal GCTs who receive cisplatin-based chemotherapy have 5-year EFS and OS rates of 90%; however, metastatic mediastinal tumors have an EFS closer to 70%.[5,6]