Intracranial germ cell tumors in Adolescents and Young Adults: European and North American consensus review, current management and future development.

Under review from Society for Neuro-Oncology (SNO), European Association for Neuro-Oncology (EANO,) and EUropean reference network for Rare Adult solid CANcers (Euracan), Dr. Mark Souweidane collaborated with 24 esteemed investigators in the US, Canada, France, Germany, and the UK to publish a consensus on the diagnosis and management of intracranial germ cell tumors (iCGT).

Intracranial germ cell tumors are rare neoplasms in the central nervous system that mainly affect adolescents and young adults between 10 and 19 years. In Europe and North America, iGCTs make up 1-3% of brain tumors, in contrast to 8-15% in East Asia.

Souweidane’s contribution from a surgical perspective on the management of this condition was essential because patients in Europe and North America are typically treated by pediatric or medical oncologists; whereas these patients are primarily under the supervision of neurosurgical teams in Asian countries (where the incidence of iCGT diagnoses is much higher).

The successful development of parallel treatment strategies in Europe and North America pays specific attention to long-term side effects resulting from the standard treatment of this complex diagnosis.

One important agreement among the cohort of investigators was that neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or CSF and/or serum analysis, minimizing the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated either as germinoma, which are non-metastatic, or as non-germinomatous germ cell tumors (NGGCT), which are metastatic. Metastatic disease is defined by a positive CSF cytology and/or distant drops in cranio-spinal MRI. Then the combination of surgery and/or chemotherapy and radiation therapy is tailored according to pre-determined grouping and staging through these less-invasive approaches.

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. It should be noted that bifocal germinomas are also 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 to address any residual disease post-chemo, and some degree of radiotherapy.

The publication reviews these various therapeutic options and the consensus made among the authors on how/when they should be incorporated into protocols.