ID #616 Treatment Outcomes and Prognostic Factors in Pediatric Atypical Teratoid/Rhabdoid Tumor: A Retrospective Analysis
Giada Del Baldo, Roberta Forestiero, Antonella Cacchione, Iside Alessi, Valentina Di Ruscio, Giocomina Megaro, Sabina Barresi, Sabrina Rossi, Selene Cipri, Evelina Miele, Maria Vinci, Giovanna Stefania Colafati, Andrea Carai, Angela MastronuzziAbstract
Background
Atypical teratoid/rhabdoid tumor (ATRT) is a rare pediatric central nervous system malignancy characterized by marked biological aggressiveness and poor prognosis. The optimal consolidation strategy remains controversial, particularly regarding the role of radiotherapy (RT) versus high-dose chemotherapy (HD-CT), due to the need to balance oncologic efficacy with long-term toxicity.
Materials and Methods
We conducted a retrospective, single-center study including 23 patients with ATRT treated over a 10-year period at Bambino Gesù Children’s Hospital, Rome, Italy. Sixteen patients were evaluable for outcome analyses, as the remaining patients were enrolled in prospective clinical trials. Patients were treated according to EU-RHAB recommendations. Clinical, radiological, surgical, molecular, and treatment-related data were retrospectively collected. Overall survival (OS) and event-free survival (EFS) were analyzed globally and according to clinical, surgical, molecular, and treatment-related variables.
Results
The median age at diagnosis was 29.5 months (6–188 months). Tumors were infratentorial in 56% of cases, and 63% of patients presented metastatic disease. Surgical management included 4 gross total resections (GTR), 2 near-total resections (NTR), and 10 subtotal resections (STR). Molecular classification was available in 12 patients (7 SHH, 3 MYC, and 2 TYR subtypes). Eight patients received RT, while seven underwent HD-CT. Germline testing revealed pathogenic variants in SMARCB1 (n = 2) and SMARCA4 (n = 1). OS was 75% at 6-months and 56.2% at 12-months, while EFS was 73.3% and 46.7%, respectively. Metastatic disease was significantly associated with worse outcome (p = 0.01). RT provided superior disease control compared with HD-CT (p = 0.05) but was associated with worse neurocognitive performance. Although not statistically significant, survival trend indicating better outcomes after GTR/NTR and poorer prognosis in patients younger than 3 years, with infratentorial tumors and MYC subtype.
Conclusion
Metastatic ATRT showed poor outcomes; RT achieved better disease control than HD-CT, emphasizing the need for risk-adapted and less toxic treatments.