CTP-12. Clinical features of 559 primary intracranial germ cell tumors: an 15-year experience of a single center in China

Incidence of primary intracranial germ cell tumors (ICGCT) in Asian countries is higher than Western countries. This study aims to describe the characteristics of ICGCT patients in China. Data on all patients with ICGCT who were seen at the Department of Neuro-oncology, Sanbo Brain Hospital, Capital Medical University from 2007 to 2022 were analyzed retrospectively. A total of 611 patients were screened. After excluding 52 cases with lost follow-up and unknown radiotherapy history, 559 cases were included in the analysis, including 286 germinomas and 273 non-germinomatous germ cell tumors (NGGCT). The median age at diagnosis was 12.8years. The male-female ratio is 2.4 to 1. 111 patients (19.9%) were adults. Adult patients were more prone to metastasis. Germinomas were mainly located in the suprasellar region, while NGGCT mainly in pineal gland. In M0 patients, whole brain radiotherapy was the most common approach, while in M+ was craniospinal radiotherapy. Whole ventricle radiotherapy was uncommon (4%). The most common chemotherapy regimen for germinomas was a combination of bleomycin, cisplatin and etoposide/tenipside; while for the NGGCT was ifosfamide combined with carboplatin/cisplatin and etoposide. For germinoma, the median recurrence-free survival (RFS) and overall survival (OS) were 146.6 months and 222 months; the 5 year RFS and OS were 74.8% and 94.6%, respectively. At relapse, two (0.7%) developed extracranial dissemination. For NGGCT, the median RFS and OS were 80.4 months and 166.7 months; the 10 year RFS and OS were 53.2% and 69.3%. At relapse, four (1.5%) developed secondary malignancies and five (1.8%) developed extracranial dissemination. Chemotherapy combined with radiotherapy could significantly improve the RFS and OS, compared with chemotherapy or radiotherapy alone. The long-term prognosis of chemotherapy followed by radiotherapy may be better than that of radiotherapy first. Higher radiation dose was associated with better prognosis.