EANO, SNO and Euracan consensus review on the current management and future development of intracranial germ cell tumors in adolescents and young adults

Abstract

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

Keywords: adolescents and young adults; brain tumors; germ cell tumor; germinoma; non-germinomatous germ cell tumor.

Fig. 1

Flow chart of management.

Fig. 2

Sagittal post-contrast MRI of the brain demonstrating a hypothalamic and infundibular mass in a 10-year-old female presenting with diabetes insipidus. Given normal serum and CSF tumor markers, a right frontal endoscopic tumor biopsy was performed which confirmed pure germinoma. Endoscopic view of the third ventricle (inset) revealing the exophytic tumor mass (a), 1 mm endoscopic biopsy forceps (b), and the bilateral hypothalami (c).

Fig. 3

This adolescent male presenting with obstructive hydrocephalus underwent an endoscopic third ventriculostomy (ETV) with simultaneous CSF sampling that confirmed a non-germinomatous germ cell tumor (NGGCT). Sagittal post-contrast MRI scans at diagnosis (left), after induction chemotherapy with normalization of tumor markers (center), and after second-look surgery via a supracerebellar infratentorial approach.