Purpose: Primary germ cell tumors (GCTs) are the most common central nervous system (CNS) neoplasm in patients with Down syndrome (DS). However, a standard-of-care has not been established due to a paucity of data. Methods: A retrospective multi-institutional analysis was conducted, in addition to a comprehensive review of the literature. Results: Ten patients from six institutions (five USA, one Brazil) were identified, in addition to 31 patients in the literature from 1975 to 2021. Of the 41 total patients (mean age 9.9 years; 61% male), 16 (39%) had non-germinomatous germ cell tumors (NGGCTs), 16 (39%) had pure germinomas and eight (19.5%) had teratomas. Basal ganglia was the most common tumor location (n=13; 31.7%), followed by posterior fossa (n=7; 17%). Nine patients (22%) experienced disease relapse or progression, of which four died from tumor progression (one germinoma, three teratomas). Sixteen patients (39%) experienced treatment-related complications, of which eight (50%) died (five germinomas, three NGGCTs). Of the germinoma patients, two died from chemotherapy-related sepsis, one from post-surgery cardiopulmonary failure, one from pneumonia and one from Moyamoya following radiation-therapy (RT). Of the NGGCT patients, one died from chemotherapy-related sepsis, one from post-surgical infection and one from pneumonia following surgery/chemotherapy/RT. Three-year overall survival was 66% for all histological types – 62% germinomas, 79% for NGGCTs, and 53% for teratomas. Conclusion: Patients with DS treated for CNS GCTs are at an increased risk of treatment-related adverse events. A different therapeutic approach may need to be considered to mitigate treatment-related complications and long-term neurocognitive sequelae.
