Abstract General Information

Title

CLINICAL CHARACTERISTICS, TREATMENT, AND SURVIVAL OUTCOME OF CHILDHOOD ATYPICAL TERATOID/RHABDOID TUMORS (ATRT): A RETROSPECTIVE 20-YEAR FOLLOW-UP STUDY

Introduction, Objectives, Methods, Results, and Conclusion.

Introduction: ATRT is a rare and aggressive central nervous system which prognosis has improved over the years due to multimodal therapy. The study aim is to evaluate clinical features, therapeutic approaches, and outcomes in children with ATRT in a single institution. Methods: We retrospectively collected clinical information on 28 pediatric patients with ATRTs treated from 2000 to 2020 and analyzed the data for this series. Results: The median age at diagnosis was 2.3 years (0-14 years). Vomit was the most common symptom at diagnosis (59%). Intracranial hypertension was present in 58.6%. Two patients presented with a synchronous tumor. Underlying genetic alterations of the SMARCB1 region were observed in two cases. The tumor’s localization was supratentorial in 11 patients (39.3%), infratentorial in 16 patients (57.1%), and spinal cord in one patient (3.6%). According to Chang's staging system, 17 patients were M0 (60,7%), three M1 (10.7%), one M2 (3.6%), seven patients M3 (25%). Gross total resection of the primary tumor was achieved in 14 patients (50%). The treatment was based on age and staging. Briefly, postoperative chemotherapy with Head-Start III Protocol followed by high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) for children under 3-years-old, and up-front radiotherapy in children ≥18 months in some cases. Children older than 3-years-old received chemotherapy and early radiotherapy after resection. Twenty-three patients under three years had the intention to perform HDCT followed by ASCT, however progressive disease (PD) was observed in seven patients and the other four died of sepsis before completing all cycles of chemotherapy. In 11/23 patients the procedure was completed, five of them are still alive. Five patients were ≥ 3-year-old, two of them died due to PD and the other two are alive. The 1 and 5-year event-free survival (EFS) were 40.1%, 9.3% and overall survival (OS) 49.3%, 17.3%, respectively. In the group that received ASCT the 5y-EFS and OS were 15.2% (p=0.012) and 30.3% (p=0.009), respectively. Patients who received upfront RT had a 5y-OS of 47.6%, while no children who did not receive RT in first treatment was alive five years after diagnosis. The first underwent complete resection, chemotherapy (ICE regimen), and radiotherapy Conclusion: HDCT followed by ASCT did not improve EFS and OS in our analysis whereas upfront radiotherapy seems to improve survival rates.

Keywords (separated by comma on a single line)

ATYPICAL TERATOID/RHABDOID TUMOR, UP-FRONT RADIOTHERAPY, SURVIVAL, SMARCB1