Treatment of Childhood Malignant Extragonadal GCTs
Note: Some citations in the text of this section are followed by a level of evidence. The PDQ Pediatric and Adult Treatment Editorial Boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)
Extragonadal germ cell tumors (GCTs) (i.e., sacrococcygeal, mediastinal, and retroperitoneal) are more common in children than adults. Children with extragonadal malignant GCTs, particularly those with advanced stage, have the highest risk of treatment failure for any GCT presentation.[2,3] In a study of prognostic factors in pediatric extragonadal malignant GCTs, age older than 12 years was the most important prognostic factor. In a multivariate analysis, children aged 12 years or older with thoracic tumors had six times the risk of death compared with children younger than 12 years with primary nonthoracic tumors. Outcome has improved remarkably, however, since the advent of platinum-based chemotherapy and the use of a multidisciplinary treatment approach.[2,5] Complete resection prior to chemotherapy may be possible in some patients without major morbidity, but for patients with locally advanced sacrococcygeal tumors, mediastinal tumors, or large pelvic tumors, tumor biopsy followed by preoperative chemotherapy can facilitate subsequent complete tumor resection and improve ultimate patient outcome.[5,6,7,8]
Antineoplastons are an experimentalcancertherapy developed by S.R. Burzynski, MD, PhD. Chemically, antineoplastons are a mixture of amino acidderivatives, peptides, and amino acids found in human blood and urine.[1,2,3,4] The developer originally isolated antineoplastons from human blood and later found the same peptides in urine. Urine was subsequently used because it was less expensive and easier to obtain. Since 1980, antineoplastons have been synthesized from commercially available chemicals...
Sacrococcygeal GCTs are very common extragonadal tumors that occur in very young children, predominately young females. They are usually diagnosed at birth, when large external lesions predominate (usually benign 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 the patients.[7,10,11] Because of advanced presentation, the management of sacrococcygeal tumors requires a multimodal approach with chemotherapy followed by delayed tumor resection. Platinum-based therapies, with either cisplatin or carboplatin, are the cornerstone of treatment. The cisplatin, etoposide, and bleomycin (PEB) regimen or the carboplatin, etoposide, and bleomycin (JEB) regimen produces event-free survival (EFS) rates of 75% to 85%; overall survival (OS) rates of 80% to 90% can be achieved.[7,8] Surgery is usually facilitated by preoperative chemotherapy, and completeness of surgical resection is a very important prognostic factor. Patients with resected tumors with negative microscopic margins have EFS rates greater than 90%; patients with microscopic margins have EFS rates of 75% to 85%; and patients with macroscopic residual disease after surgery have EFS rates less than 40%. In any patient with a sacrococcygeal GCT, resection of the coccyx is mandatory.[7,8]
Mediastinal GCTs account for 15% to 20% of malignant nongonadal, extracranial GCTs in children. The histology of mediastinal GCT is dependent on age, with teratomas predominating among infants and with 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%, but an EFS closer to 70% occurs with metastatic mediastinal tumors.[5,6] Most mediastinal GCTs in adolescents and young adults occur in males and 50% have cytogenetic changes consistent with Klinefelter syndrome. The age of presentation is younger in patients with Klinefelter syndrome.[12,13] As with sacrococcygeal tumors, primary chemotherapy is usually necessary to facilitate surgical resection of mediastinal GCTs, and the completeness of resection is a very important prognostic indicator.[6,14] Survival rates for the older adolescent and young adult population with mediastinal tumors are generally less than 60%.[4,15,16,17]; Level of evidence: 3iiA (Refer to the PDQ summary on Extragonadal Germ Cell Tumors Treatment for more information.)