The outcomes of pediatric extracranial malignant germ cell tumors: A decade of experience from a single institution in Southern Vietnam.

Background: Extracranial malignant germ cell tumors (GCTs) generally exhibit favorable outcomes with contemporary therapeutic approaches. However, the outcomes of pediatric GCTs in Vietnam remain unclear. This study aims to evaluate the clinical features, treatment modalities, and prognostic factors associated with survival outcomes in children with GCTs treated at Children's Hospital Number 2 (CH2) in Ho Chi Minh City, Vietnam.

Methods: We conducted a retrospective cohort study involving pediatric patients with GCTs treated at CH2 between January 1, 2011, and July 30, 2019. Data were extracted from medical records and entered into REDCap for analysis using SPSS version 20.0 (IBM Corporation, Armonk, NY). Descriptive statistics were reported as mean ± standard deviation, unless otherwise specified. Overall survival (OS) and event-free survival (EFS) rates were estimated using the Kaplan-Meier method, and the log-rank test was employed to assess the significance of potential prognostic factors.

Results: A total of 69 patients with a median age of 25 months were included in the study. Of these, 48 (69.9 %) had gonadal tumors, and 21 (30.4 %) had extragonadal tumors. The median alpha-fetoprotein (AFP) level at diagnosis was 2,589 kU/L, with 26 (37.7 %) patients presenting with AFP levels exceeding 10,000 kU/L. All patients underwent surgical resection followed by platinum-based chemotherapy (carboplatin in 92.8 % and cisplatin in 7.2 %). The incidence of grade 3-4 toxicities (neutropenia, febrile neutropenia, and thrombocytopenia) varied between 3.5 % and 19.4 % per chemotherapy cycle. The mean follow-up duration was 53.3 months, with a relapse rate of 5.8 % and an abandonment rate of 11.6 %. The 5-year OS and EFS rates were 92.5 % and 91 %, respectively. EFS was significantly higher in patients with gonadal tumors compared to those with extragonadal tumors (95.7 % vs 84.4 %, p = 0.035). Additionally, OS was significantly better in patients with stage I-II tumors compared to those with stage III-IV (100 % vs 86.2 %, p = 0.03), in patients with AFP levels <10,000 kU/L compared to those with AFP >10,000 kU/L (97.6 % vs 84 %, p = 0.041), and in patients who did not abandon treatment (94.9 % vs 77 %, p = 0.044).

Conclusions: The outcomes of pediatric extracranial malignant germ cell tumors in this cohort were excellent, with relatively low early treatment-related toxicity. Reducing treatment abandonment and identifying high-risk patients for intensified therapy may further improve survival outcomes in this setting.