Epidemiologic analysis of 1,442 children and adolescents registered in the German germ cell tumor protocols

Abstract

Background Germ cell tumors (GCTs) constitute a heterogeneous group of tumors that significantly vary with respect to their clinical presentation and biology. The objective of this analysis was to analyze a large population‐based pediatric cohort of GCTs and to evaluate the parameters age, sex, site of the tumor, histology, and potential correlations between these parameters. Procedure Between 1981 and 2000, 1,442 patients were prospectively enrolled onto the German protocols for testicular and non‐testicular GCTs. Tumors were histologically classified according to the WHO. Results We observed a bimodal age distribution with a first peak during infancy and a second after the onset of puberty. At birth, almost all tumors were teratomas, sometimes with microfoci of yolk sac tumor, which on the other hand, was the predominant histology during childhood. After the onset of puberty, germinomatous GCTs represented the most frequent histological subtype, and malignant non‐germinomatous GCTs often presented as mixed tumors with choriocarcinoma and embryonal carcinoma components. During infancy, non‐gonadal GCTs accounted for the majority of GCTs, while after the onset of puberty, gonadal GCTs predominated. Notably, among non‐gonadal GCTs, there was a female predominance during childhood and a strong male predominance during adolescence. Conclusions Two separate groups of GCTs with distinct clinical features relevant for differential diagnosis and the diagnostic assessment can be distinguished. This observation correlates with genetic studies that reveal different genetic changes in childhood and adolescence GCTs. Further studies are needed to elucidate the molecular mechanisms of germ cell and GCT development that account for the age‐ and sex‐dependent clinical manifestation.