GERM-03. CLINICAL FEATURES AND OUTCOME OF CHILDREN WITH INTRACRANIAL NON-GERMINOMATOUS GERM CELL TUMORS: A POPULATION-BASED STUDY IN HONG KONG

Abstract

The incidence of central nervous system non-germinomatous germ cell tumor (NGGCT) is four times higher in Chinese children than in the Western population. Reports on the outcome of Asian patients are nonetheless limited. Here we aim to summarize the experience of treating pediatric NGGCT in Hong Kong. Leveraging a population-wide pediatric oncology database, Chinese children with NGGCT diagnosed from 2002–2020 (n=43) were retrospectively studied. The diagnoses of NGGCT were made either with elevation in tumor markers (AFP/hCG; n=19), or by histology with/without concomitant raise in tumor markers (n=24). Most patients were treated with a combination of chemotherapy (cisplatin/etoposide/bleomycin, carboplatin/etoposide or carboplatin/etoposide/ifosfamide) and radiation (craniospinal+boost, whole ventricular+boost, or focal). The male:female ratio was 37:6, and the median age of diagnosis was 11.2 years. Primary tumor locations were pineal in 18, sellar/suprasellar in 12, basal ganglial in 9, supratentorial in 3 and posterior fossa in 1. Three had metastasis. Among the patients diagnosed by histology (n=24), 12 had mixed GCT, 8 had malignant/immature teratoma, 3 had embryonal carcinoma, and 1 had yolk sac tumor. With a median follow-up of 8 years, 8 patients progressed (local=7, distant=1), and 9 patients died (progression=5, palliative treatment for congenital tumors=2, sepsis=1, procedural complication=1). The respective 5-year PFS and OS were 74.9±6.9% and 82.2±6.1%. In multivariate analysis, high serum hCG level and no radiation use were significantly associated with inferior PFS. Outcome did not differ according to chemotherapeutic reagents used or radiation fields. Four patients had growing teratoma syndrome. Long-term neuroendocrine sequalae were common. In conclusion, children with NGGCT had reasonable outcome after multi-modal therapy in Hong Kong. Effort should be made to minimize tumor and treatment-related toxicities. The role of tumor markers for risk-stratification within NGGCT needs to be further interrogated.