CTNI-60. NEOAJUVANT CHEMOTHERAPY FOLLOWED BY CRANIOSPINAL IRRADIATION FOR INTRACRANIAL NGGCTS: CLINICAL OUTCOMES AND AGE-STRATIFIED TOXICITIES IN A COHORT OF 111 PATIENTS

Abstract

Abstract BACKGROUND Intracranial non-germinomatous germ cell tumors (NGGCTs) are rare tumors with limited studies available worldwide. Despite significantly improved survivals, there are still approximately 30% of patients experience relapse and require salvage treatment. This study aimed to access the clinical-pathological features and prognostic factors with specific interests to recurrence as well as adverse effects. METHODS From June 2005 and December 2018, 111 consecutive intracranial NGGCTs patients (87 localized stage and 24 metastatic stage) diagnosed based on histological confirmation, or alternatively by clinical presentation, radiological outcomes and elevated tumor markers were retrospectively analyzed. RESULTS After a median follow-up of 46.2 months, Three- and five- year OS were 83.5% ± 3.9% and 78.6% ± 5.1%, respectively. Three- and five- year EFS were 71.0% ± 4.8% and 64.7% ± 5.7%, respectively. Patients received craniospinal irradiation (CSI) integrated combined treatment yielded superior 3-year OS (P=0.007), EFS (P=0.002), and relapse rate (P=0.004) compared to those without CSI. A combination of minimum 4 cycles of induction chemotherapy and CSI integrated approach was the independent prognostic factor (P=0.007) conferring favorable 3-year OS and EFS of 93.9%±3.5% and 84.0%±5.4%, respectively. Poor prognosis of histological subtypes were particularly benefit from this treatment modality (P< 0.001). Age-thresholds for risking therapy-related thrombocytopenia and growth impairment by ROC analysis were 14 (AUC=0.752, P< 0.0001) and 11.5 (AUC=0.806, P< 0.01) yr., respectively. CONCLUSIONS Our study suggested that multimodal approach consisting of ≥4 cycles of induction chemotherapy and CSI plus focal boost with or without second-look surgery was recommended for NGGCTs. However, CSI should be used with caution when patients < 11.5-yr due to growth impairment. More precise risk stratifications are highly demanded for delivery of the most appropriate management in the future.