Background: Germ cell tumors (GCT) are the most common central nervous system (CNS) tumors in individuals with Down syndrome. Patients with Down syndrome treated with CNS irradiation are at increased risk of developing cerebrovascular complications such as moyamoya disease. Embryonal carcinoma components are recognized to be more resistant to conventional chemotherapy and radiotherapy and confer a very poor prognosis. CD30 is a member of the tumor necrosis factor-receptor superfamily. CD30+ has a limited expression in normal cells but is the defining marker for embryonal carcinoma. Brentuximab-vedotin is a novel antibody-drug conjugate consisting of the chimeric anti-CD30 antibody conjugated to an anti-tubulin synthetic analog monomethyl auristatin E.
Methods: A retrospective review of the patient's records was conducted in September 2017.
Results: We report upon our management of a teenage girl with Down syndrome and a suprasellar pure embryonal carcinoma utilizing an intensive chemotherapy regimen followed by brentuximab-vedotin without irradiation. The patient received two cycles of carboplatin and etoposide interspersed with one cycle of cyclophosphamide and etoposide for induction followed by three cycles of marrow-ablative thiotepa and carboplatin rescued by autologous hematopoietic stem cell. Finally, She received six cycles of intravenous brentuximab-vedotin. The patient continues without evidence of recurrent tumor by MRI and tumor marker surveillance 24 months since diagnosis, with no adverse sequelae of her treatment.
Conclusions: Brentuximab-vedotin may provide a selective and safe alternative (or adjunct) to radiotherapy in the management of patients with CD30-positive CNS embryonal carcinoma, especially for those patients at high risk of developing irradiation-related complications.
Keywords: Brentuximab-vedotin; Down syndrome; Embryonal carcinoma; Intracranial germ cell tumors; Moyamoya disease.