gms | German Medical Science

Germ cell tumors (GCTs) are heterogeneous and vary with respect to clinical presentation, histology and biology. Two incidence peaks are observed within the pediatric tumors; during infancy and early childhood, mainly as teratomas and yolk sac tumors that predominantly arise in the sacrococcygeal region or testes and in the second decade predominantly as mixed malignant gonadal, mediastinal and CNS germ cell tumors. Histology and age correlate with the genetic profiles. In malignant GCT of children < 10 years an isochromosome 12p has rarely been found, whereas aberrations at chromosomes 1, 6, and 20 and the sex chromosomes occur most often. This requires a multimodal treatment including the pediatric oncologist in cooperation with the appropriate surgical disciplines and the radiotherapist. During the past, a dramatic improvement of the prognosis of malignant GCTs in the adult and the pediatric population has been achieved. This progress is mainly attributed to the utilization of a cisplatinum-based combination chemotherapy. The first pediatric trials have been designed based on the experience in malignant testicular GCT in adults. These studies have soon revealed the particular clinical and biological features of childhood GCT. Therapy is more specifically tailored to the pediatric setting by stratification of chemotherapy according to risk groups in respect to the parameters age, histology, primary site and stage. From 1982 on, the German protocols for testicular (MAHO) and nontesticular (MAKEI) GCTs included cisplatinum- and etoposide based chemotherapy regimens. As a result of the excellent event-free survival rates above 80% the cumulative chemotherapy was step-wise reduced from a maximum of 8 cycles to 6 and currently 4 to 5 cycles in poor prognostic patients which did not affect outcome. Under protocol guidelines complete tumor resection is the most important risk factor therefore. In locally advanced or metastatic tumors a neoadjuvant approach is used as it facilitates complete tumor resection and thereby reduces the need for second look surgery. In MAKEI 96, an expectant watch-and-wait strategy is recommended for patients with completely resected low stage tumors. This spares chemotherapy in approximately 25% of patients with malignant GCT. Special emphasis has to be given to extragonadal teratoma with malignant microfoci as in half of all relapsing teratoma patients of the pediatric age group malignant histology (yolk sac tumor) is predominant. Supported by Deutsche Krebshilfe