ID #1126 Treatment Strategies and Early Mortality in Pediatric Central Nervous System Non-Germinomatous Germ Cell Tumors in Mexico: A Multicenter Experience

Background

Central nervous system non-germinomatous germ cell tumors (NGGCT) are rare and aggressive malignancies with inferior outcomes compared with germinomas. In low- and middle-income countries (LMICs), limitations in diagnostic, surgical, and supportive care resources may further affect treatment delivery and survival. Multicenter real-world data from LMIC settings remain scarce.

Objectives

To describe treatment strategies and evaluate survival outcomes of pediatric CNS NGGCT treated in an LMIC context, with emphasis on treatment-related morbidity, and timing of mortality.

Methods

Retrospective multicenter cohort study including pediatric patients with CNS NGGCT treated at eight Mexican hospitals (2013-2025). Clinical characteristics, histology, tumor markers, treatment modalities, treatment-related complications, and outcomes were analyzed. Overall survival (OS) and EFS were estimated using Kaplan–Meier.

Results

A total of 39 patients were included. Median age at diagnosis was 10.2 years, 76.9% were male. Histologic subtypes included choriocarcinoma(28.2%), yolk sac tumor(23.7%), mixed germ cell tumors(23.7%), immature teratoma(7.9%), and embryonal carcinoma(2.6%). Only 16.2% had no marker elevation, 35.1% showed concurrent AFP and β-hCG elevation; mean AFP level: 1,488.1ng/mL. Primary sites were suprasellar (46.2%), pineal (41.0%), and bifocal (7.7%). Most patients presented with localized disease (87.2%).

Diagnosis was established by imaging and/or tumor markers(61.5%), surgical resection(28.2%), and biopsy(10%). Combined modality treatment predominated, 54.1% receiving chemotherapy followed by radiotherapy; 2.7% received radiotherapy alone. Chemotherapy regimens included alternating carboplatin/etoposide with ifosfamide/etoposide (46.7%), ICE (20%), and carboplatin/etoposide, PEI, or PEB/JEB(6.7% each). 4-6 chemotherapy cycles were administered in 63.3% of patients.

Radiotherapy strategies included CSI (40%), WVI (25%), and WB in (15%). Treatment-related morbidity was substantial: 73.3% required inpatient management, 60% experienced chemotherapy delays, 25.6% developed surgical infectious complications. Residual tumor after chemotherapy was observed in 15 patients (2 mature teratoma and 1 viable tumor). 1- and 10-year OS were 58.1% and 54.2%, respectively, while 1- and 10-year EFS were 54.4% and 42.6%, indicating that most mortality occurred early during treatment. Residual tumor after chemotherapy was strongly associated with inferior EFS (5-year EFS 13.6% vs. 68.4%; p < 0.001; HR 3.5).

Conclusions

In this multicenter LMIC cohort outcomes remain inferior to those reported in contemporary cooperative group trials. The minimal difference between 1- and 10-year survival highlights that deaths predominantly occur during early treatment phases. In contrast, COG ACNS1123 and SIOP NGGCT studies have demonstrated improved survival through risk-adapted multimodal therapy, treatment standardization, and optimized supportive care. These findings underscore the need to harmonize treatment strategies, and improve supportive care infrastructure in LMIC settings to reduce early mortality.