Comparative treatment results of children with atypical teratoid/rhabdoid tumor of the central nervous system in the younger age group

Abstract

Introduction. Atypical teratoid/rhabdoid tumor (ATRT) of the central nervous system (CNS) belongs to the embryonic group, occurs mainly in children under 3 years of age and is characterized by an extremely aggressive clinical course and unfavorable outcome. However, there is not enough data about the heterogeneity of the clinical course of CNS ATRT and the role of clinical and therapeutic prognostic factors in patients under 1 year of age and 1–3 years of age.The aim of this study was to conduct a comparative evaluation of treatment results in children with CNS ATRT in the indicated age groups.Materials and methods. From 2008 till 2021 years 106 patients were included in this study. Each patient underwent a therapeutic program according to determined protocol (ATRT-2006, MUV-ATRT, EU-RHAB and individual variant). All patients were divided into 2 groups according to age: from 1 to 12 months – 41 patients, from 13 to 36 months – 65. Median of the age was 16 (9–23) months. These cohorts of patients (1–12 months and 13–36 months) were comparable in clinical and therapeutic characteristics depending on gender, localization of the primary tumor site, stage of the disease, extent of surgical resection, therapeutic protocol, number of patients, who underwent radiation therapy (RT), high-dose chemotherapy (HDCT) with autologous hematopoietic stem cell transplantation (auto-HSCT), intrathecal/ intraventricular chemotherapy.Results. At the time of analysis 48 (45.3 %) patients were alive, 58 (54.7 %) patients died, of whom 52 (90 %) from disease progression and 6 (10 %) from therapeutic complications. One-year progression-free survival (PFS) in the group from 1 to 12 months was 32 %, 2-year – 18 %, 5-year – 18 %; one-year overall survival (OS) – 53 %, 2-year – 29 %, 5-year – 25 % with a median follow-up 8 and 13 months respectively. One-year PFS in the group from 13 to 36 months was 61 %, 2-year – 36 %, 5-year – 33 %; one-year OS – 86 %, 2-year – 67 %, 5-year – 49 % with a median follow-up 19 and 38 months respectively. In our study we identified the main predictors of the PFS and OS improvement in patients with ATRT CNS of each age group. In the 1–12 month group, these factors were: absence of metastatic involvement, MUV-ATRT therapeutic protocol, RT and HDCT with auto-HSCT; in the 13–36 months group: gross total/near gross total resection of the primary tumor cite, ATRT-2006 therapeutic protocol and RT.Conclusion. Despite the fact, that the presence of a diagnosis of ATRT CNS in children under 3 years of age is usually associated with a high risk of disease progression and recurrence, the results of our study demonstrate the heterogeneity of the clinical and therapeutic profile in this age group of patients.